diff --git a/curriculum/challenges/espanol/01-responsive-web-design/basic-css/change-a-variable-for-a-specific-area.md b/curriculum/challenges/espanol/01-responsive-web-design/basic-css/change-a-variable-for-a-specific-area.md
index 405c676bf2..15376cef59 100644
--- a/curriculum/challenges/espanol/01-responsive-web-design/basic-css/change-a-variable-for-a-specific-area.md
+++ b/curriculum/challenges/espanol/01-responsive-web-design/basic-css/change-a-variable-for-a-specific-area.md
@@ -11,7 +11,7 @@ dashedName: change-a-variable-for-a-specific-area
 
 Cuando creas tus variables en `:root`, el valor de esa variable quedará establecido para toda la página.
 
-Luego podrás sobreescribir estas variables, configurándolas de nuevo dentro de un elemento específico.
+Puedes entonces sobreescribir estas variables configurándolas nuevamente con un selector específico.
 
 # --instructions--
 
@@ -27,7 +27,7 @@ assert(
 );
 ```
 
-La clase `penguin` no debe contener la propiedad `background-color`
+La clase `penguin` no debe de tener la propiedad `background-color`.
 
 ```js
 assert(
diff --git a/curriculum/challenges/espanol/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md b/curriculum/challenges/espanol/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md
index dcb072f9b6..29a2b0c104 100644
--- a/curriculum/challenges/espanol/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md
+++ b/curriculum/challenges/espanol/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md
@@ -11,7 +11,7 @@ dashedName: align-elements-using-the-justify-content-property
 
 Algunas veces los elementos flexibles dentro de un contenedor flexible no llenan todo el espacio del contenedor. Es común querer indicarle al CSS cómo alinear y espaciar los elementos flexibles de una determinada manera. Afortunadamente, la propiedad `justify-content` tiene varias opciones para hacer esto. Pero primero, hay que entender alguna terminología importante antes de revisar dichas opciones.
 
-[Aquí hay una imagen útil que muestra una fila para ilustrar los conceptos siguientes.](https://www.w3.org/TR/css-flexbox-1/images/flex-direction-terms.svg)
+[Aquí hay una imagen útil del W3C que ilustra los conceptos siguientes para un contenedor 'row' flex.](https://www.w3.org/TR/css-flexbox-1/images/flex-direction-terms.svg)
 
 Recuerda que establecer un contenedor flexible como fila coloca los elementos flexibles uno al lado del otro de izquierda a derecha. Un contenedor flexible establecido como columna coloca los elementos flexibles apilados verticalmente de arriba a abajo. Para cada uno, la dirección en la que están dispuestos los elementos flexibles se llama el **eje principal**. Para una fila, esta es una línea horizontal que recorta cada elemento. Y para una columna, el eje principal es una línea vertical a través de los elementos.
 
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md
index c6ee9f61fc..b55fc9aaed 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/convert-celsius-to-fahrenheit.md
@@ -8,9 +8,9 @@ dashedName: convert-celsius-to-fahrenheit
 
 # --description--
 
-El algoritmo para convertir de Celsius a Fahrenheit es la temperatura en Celsius multiplicado por `9/5`, más `32`.
+La fórmula para convertir de Celsius a Fahrenheit es la temperatura en Celsius multiplicado por `9/5`, más `32`.
 
-Se te da una variable `celsius` que representa una temperatura en Celsius. Utiliza la variable `fahrenheit` ya definida y asígnale la temperatura Fahrenheit equivalente a la temperatura Celsius dada. Utiliza el algoritmo mencionado arriba para ayudar a convertir la temperatura en Celsius a Fahrenheit.
+Se te da una variable `celsius` que representa una temperatura en Celsius. Utiliza la variable `fahrenheit` ya definida y asígnale la temperatura Fahrenheit equivalente a la temperatura Celsius dada. Utiliza la fórmula mencionada anteriormente para ayudarte a convertir la temperatura Celsius a Fahrenheit.
 
 # --hints--
 
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/check-if-an-object-has-a-property.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/check-if-an-object-has-a-property.md
index 2d0ba9fb48..e4bf6b4837 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/check-if-an-object-has-a-property.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/check-if-an-object-has-a-property.md
@@ -19,7 +19,7 @@ Ambos devuelven `true`.
 
 # --instructions--
 
-Termina de escribir la función para que devuelva "true" sólo si el objeto pasado contiene los cuatro nombres, `Alan`, `Jeff`, `Sarah` y `Ryan`, y devuelve false de lo contrario.
+Termina de escribir la función para que devuelva `true` si el objeto pasado contiene los cuatro nombres, `Alan`, `Jeff`, `Sarah` and `Ryan` y devuelva `false` en caso contrario.
 
 # --hints--
 
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/remove-items-using-splice.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/remove-items-using-splice.md
index fe1f9c285e..c39f7349f8 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/remove-items-using-splice.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-data-structures/remove-items-using-splice.md
@@ -10,7 +10,7 @@ dashedName: remove-items-using-splice
 
 Bien, ya hemos aprendido a eliminar elementos al principio y al final de los arreglos utilizando `shift()` y `pop()`, pero ¿qué pasa si queremos eliminar un elemento de alguna parte del medio? ¿O eliminar más de un elemento a la vez? Pues bien, ahí es donde entra `splice()`. `splice()` nos permite hacer precisamente eso: **eliminar cualquier número de elementos consecutivos** de cualquier parte de un arreglo.
 
-`splice()` puede tomar hasta 3 parámetros, pero por ahora, nos centraremos sólo en los 2 primeros. Los dos primeros parámetros de `splice()` son enteros que representan índices, o posiciones, del arreglo que llama `splice()`. Y recuerda que los arreglos están *indexados en cero*, por lo que para indicar el primer elemento de un arreglo, usaríamos `0`. El primer parámetro de `splice()` representa el índice del arreglo a partir del cual se empiezan a eliminar los elementos, mientras que el segundo parámetro indica el número de elementos a eliminar. Por ejemplo:
+`splice()` puede tomar hasta 3 parámetros, pero por ahora, nos centraremos sólo en los 2 primeros. Los primeros dos parámetros de `splice()` son enteros que representan índices, o posiciones, de elementos en el arreglo a la que `splice()` está siendo llamado. Y recuerda que los arreglos están *indexados en cero*, por lo que para indicar el primer elemento de un arreglo, usaríamos `0`. El primer parámetro de `splice()` representa el índice del arreglo a partir del cual se empiezan a eliminar los elementos, mientras que el segundo parámetro indica el número de elementos a eliminar. Por ejemplo:
 
 ```js
 let array = ['today', 'was', 'not', 'so', 'great'];
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
index 96e7c2919b..e1c9d1ae4b 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
@@ -19,17 +19,15 @@ Los índices de los arreglos se escriben en la misma notación de corchetes que
 
 ```js
 const array = [50, 60, 70];
-array[0];
+console.log(array[0]);
 const data = array[1];
 ```
 
-`array[0]` ahora es `50` y `data` tiene el valor `60`.
-
-**Nota:** No debe haber espacios entre el nombre del arreglo y los corchetes, como `array [0]`. Aunque JavaScript pueda procesar esto correctamente, puedes confundir a otros programadores al leer tu código.
+`console.log(array[0])` imprime `50`, y `data` tiene el valor `60`.
 
 # --instructions--
 
-Crea una variable llamada `myData` e iguálala al primer valor de `myArray` usando notación de corchetes.
+Crea una variable llamada `myData` y establécela para que sea igual al primer valor de `myArray` usando notación de corchetes.
 
 # --hints--
 
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/record-collection.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/record-collection.md
index 74d1e180a1..340b9db0eb 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/record-collection.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/record-collection.md
@@ -31,13 +31,13 @@ assert(
 );
 ```
 
-Después de `updateRecords(recordCollection, 5439, "tracks", "Take a Chance on Me")`, `tracks` debe tener la cadena `Take a Chance on Me` como último elemento.
+Después `updateRecords(recordCollection, 5439, "tracks", "Take a Chance on Me")`, `tracks` debe de tener la cadena `Take a Chance on Me` como el último y único elemento.
 
 ```js
 assert(
-  updateRecords(_recordCollection, 5439, 'tracks', 'Take a Chance on Me')[5439][
-    'tracks'
-  ].pop() === 'Take a Chance on Me'
+  updateRecords(_recordCollection, 5439, 'tracks', 'Take a Chance on Me') &&
+  _recordCollection[5439]['tracks'].length === 1 &&
+  _recordCollection[5439]['tracks'].pop() === 'Take a Chance on Me'
 );
 ```
 
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/understanding-uninitialized-variables.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/understanding-uninitialized-variables.md
index e685634483..17f5d499ed 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/understanding-uninitialized-variables.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/basic-javascript/understanding-uninitialized-variables.md
@@ -9,7 +9,7 @@ dashedName: understanding-uninitialized-variables
 
 # --description--
 
-Cuando las variables de JavaScript son declaradas, tienen un valor inicial de `undefined` (indefinido). Si haces una operación matemática en una variable `undefined`, tu resultado será `NaN` lo que significa <dfn>"Not a Number"</dfn> (no es un número). Si concatenas una cadena con una variable `undefined`, obtendrás una <dfn>cadena</dfn> literal con valor `undefined`.
+Cuando las variables de JavaScript son declaradas, tienen un valor inicial de `undefined` (indefinido). Si haces una operación matemática en una variable `undefined`, tu resultado será `NaN` lo que significa <dfn>"Not a Number"</dfn> (no es un número). Si concatenas una cadena con una variable `undefined`, obtendrás una <dfn>cadena</dfn> de `undefined`.
 
 # --instructions--
 
diff --git a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/everything-be-true.md b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/everything-be-true.md
index ec34c9f089..71d0e997b6 100644
--- a/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/everything-be-true.md
+++ b/curriculum/challenges/espanol/02-javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/everything-be-true.md
@@ -18,120 +18,123 @@ Recuerda, puedes acceder a las propiedades del objeto mediante la notación de p
 
 # --hints--
 
-`truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex")` debe devolver `true`.
+`truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "isBot")` debe devolver `false`.
 
 ```js
-assert.strictEqual(
-  truthCheck(
-    [
-      { user: 'Tinky-Winky', sex: 'male' },
-      { user: 'Dipsy', sex: 'male' },
-      { user: 'Laa-Laa', sex: 'female' },
-      { user: 'Po', sex: 'female' }
-    ],
-    'sex'
-  ),
-  true
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Quincy", role: "Founder", isBot: false },
+    { name: "Naomi", role: "", isBot: false },
+    { name: "Camperbot", role: "Bot", isBot: true }
+  ],
+  "isBot"), false);
 ```
 
-`truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex")` debe devolver `false`.
+`truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "name")` debe devolver `true`.
 
 ```js
-assert.strictEqual(
-  truthCheck(
-    [
-      { user: 'Tinky-Winky', sex: 'male' },
-      { user: 'Dipsy' },
-      { user: 'Laa-Laa', sex: 'female' },
-      { user: 'Po', sex: 'female' }
-    ],
-    'sex'
-  ),
-  false
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Quincy", role: "Founder", isBot: false },
+    { name: "Naomi", role: "", isBot: false },
+    { name: "Camperbot", role: "Bot", isBot: true }
+  ],
+  "name"), true);
 ```
 
-`truthCheck([{"user": "Tinky-Winky", "sex": "male", "age": 0}, {"user": "Dipsy", "sex": "male", "age": 3}, {"user": "Laa-Laa", "sex": "female", "age": 5}, {"user": "Po", "sex": "female", "age": 4}], "age")` debe devolver `false`.
+`truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "role")` debe devolver `false`.
 
 ```js
-assert.strictEqual(
-  truthCheck(
-    [
-      { user: 'Tinky-Winky', sex: 'male', age: 2 },
-      { user: 'Dipsy', sex: 'male', age: 0 },
-      { user: 'Laa-Laa', sex: 'female', age: 5 },
-      { user: 'Po', sex: 'female', age: 4 }
-    ],
-    'age'
-  ),
-  false
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Quincy", role: "Founder", isBot: false },
+    { name: "Naomi", role: "", isBot: false },
+    { name: "Camperbot", role: "Bot", isBot: true }
+  ],
+  "role"), false);
 ```
 
-`truthCheck([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true}, {"name": "FastForward", "onBoat": null}], "onBoat")` debe devolver `false`.
+`truthCheck([{name: "Pikachu", number: 25, caught: 3}, {name: "Togepi", number: 175, caught: 1}], "number")` debe devolver `true`.
 
 ```js
-assert.strictEqual(
-  truthCheck(
-    [
-      { name: 'Pete', onBoat: true },
-      { name: 'Repeat', onBoat: true },
-      { name: 'FastForward', onBoat: null }
-    ],
-    'onBoat'
-  ),
-  false
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Pikachu", number: 25, caught: 3 },
+    { name: "Togepi", number: 175, caught: 1 },
+  ],
+  "number"), true);
 ```
 
-`truthCheck([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true, "alias": "Repete"}, {"name": "FastForward", "onBoat": true}], "onBoat")` debe devolver `true`.
+`truthCheck([{name: "Pikachu", number: 25, caught: 3}, {name: "Togepi", number: 175, caught: 1}, {name: "MissingNo", number: NaN, caught: 0}], "caught")` debe devolver `false`.
 
 ```js
-assert.strictEqual(
-  truthCheck(
-    [
-      { name: 'Pete', onBoat: true },
-      { name: 'Repeat', onBoat: true, alias: 'Repete' },
-      { name: 'FastForward', onBoat: true }
-    ],
-    'onBoat'
-  ),
-  true
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Pikachu", number: 25, caught: 3 },
+    { name: "Togepi", number: 175, caught: 1 },
+    { name: "MissingNo", number: NaN, caught: 0 },
+  ],
+  "caught"), false);
 ```
 
-`truthCheck([{"single": "yes"}], "single")` debe devolver `true`.
+`truthCheck([{name: "Pikachu", number: 25, caught: 3}, {name: "Togepi", number: 175, caught: 1}, {name: "MissingNo", number: NaN, caught: 0}], "number")` debe devolver `false`.
 
 ```js
-assert.strictEqual(truthCheck([{ single: 'yes' }], 'single'), true);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Pikachu", number: 25, caught: 3 },
+    { name: "Togepi", number: 175, caught: 1 },
+    { name: "MissingNo", number: NaN, caught: 0 },
+  ],
+  "number"), false);
 ```
 
-`truthCheck([{"single": ""}, {"single": "double"}], "single")` debe devolver `false`.
+`truthCheck([{name: "Quincy", username: "QuincyLarson"}, {name: "Naomi", username: "nhcarrigan"}, {name: "Camperbot"}], "username")` debe devolver `false`.
 
 ```js
-assert.strictEqual(
-  truthCheck([{ single: '' }, { single: 'double' }], 'single'),
-  false
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "Quincy", username: "QuincyLarson" },
+    { name: "Naomi", username: "nhcarrigan" },
+    { name: "Camperbot" }
+  ],
+  "username"), false);
 ```
 
-`truthCheck([{"single": "double"}, {"single": undefined}], "single")` debe devolver `false`.
+`truthCheck([{name: "freeCodeCamp", users: [{name: "Quincy"}, {name: "Naomi"}]}, {name: "Code Radio", users: [{name: "Camperbot"}]}, {name: "", users: []}], "users")` debe devolver `true`.
 
 ```js
-assert.strictEqual(
-  truthCheck([{ single: 'double' }, { single: undefined }], 'single'),
-  false
-);
+assert.strictEqual(truthCheck(
+  [
+    { name: "freeCodeCamp", users: [{ name: "Quincy" }, { name: "Naomi" }] },
+    { name: "Code Radio", users: [{ name: "Camperbot" }] },
+    { name: "", users: [] },
+  ],
+  "users"), true);
 ```
 
-`truthCheck([{"single": "double"}, {"single": NaN}], "single")` debe devolver `false`.
+`truthCheck([{id: 1, data: {url: "https://freecodecamp.org", name: "freeCodeCamp"}}, {id: 2, data: {url: "https://coderadio.freecodecamp.org/", name: "CodeRadio"}}, {id: null, data: {}}], "data")` debe devolver `true`.
 
 ```js
-assert.strictEqual(
-  truthCheck([{ single: 'double' }, { single: NaN }], 'single'),
-  false
-);
+assert.strictEqual(truthCheck(
+  [
+    { id: 1, data: { url: "https://www.freecodecamp.org", name: "freeCodeCamp" } },
+    { id: 2, data: { url: "https://coderadio.freecodecamp.org/", name: "CodeRadio" } },
+    { id: null, data: {} },
+  ],
+  "data"), true);
+```
+
+`truthCheck([{id: 1, data: {url: "https://freecodecamp.org", name: "freeCodeCamp"}}, {id: 2, data: {url: "https://coderadio.freecodecamp.org/", name: "CodeRadio"}}, {id: null, data: {}}], "id")` debe devolver `false`.
+
+```js
+assert.strictEqual(truthCheck(
+  [
+    { id: 1, data: { url: "https://www.freecodecamp.org", name: "freeCodeCamp" } },
+    { id: 2, data: { url: "https://coderadio.freecodecamp.org/", name: "CodeRadio" } },
+    { id: null, data: {} },
+  ],
+  "id"), false);
 ```
 
 # --seed--
@@ -143,7 +146,7 @@ function truthCheck(collection, pre) {
   return pre;
 }
 
-truthCheck([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex");
+truthCheck([{name: "Quincy", role: "Founder", isBot: false}, {name: "Naomi", role: "", isBot: false}, {name: "Camperbot", role: "Bot", isBot: true}], "isBot");
 ```
 
 # --solutions--
diff --git a/curriculum/challenges/italian/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md b/curriculum/challenges/italian/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md
index a8cef073e6..0c317e4302 100644
--- a/curriculum/challenges/italian/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md
+++ b/curriculum/challenges/italian/01-responsive-web-design/css-flexbox/align-elements-using-the-justify-content-property.md
@@ -9,9 +9,9 @@ dashedName: align-elements-using-the-justify-content-property
 
 # --description--
 
-Certe volte gli oggetti flex all'interno di un contenitore flex non riempiono tutto lo spazio del contenitore. È comune voler dire a CSS di allineare e spaziare gli elementi flex in una certa maniera. Fortunatamente, la proprietà `justify-content` ha diverse opzioni per farlo. Ma prima, c'è un pò di terminologia importante da comprendere prima di rivedere queste opzioni.
+Certe volte gli oggetti flex all'interno di un contenitore flex non riempiono tutto lo spazio del contenitore. È comune voler dire a CSS di allineare e spaziare gli elementi flex in una certa maniera. Fortunatamente, la proprietà `justify-content` ha diverse opzioni per farlo. Ma prima, c'è un po' di terminologia importante da capire prima di rivedere queste opzioni.
 
-[Ecco un'immagine molto utile che mostra una riga per illustrare i concetti qui sotto.](https://www.w3.org/TR/css-flexbox-1/images/flex-direction-terms.svg)
+[Ecco una immagine utile da W3C che illustra i concetti sotto per un contenitore 'row' (riga) flex.](https://www.w3.org/TR/css-flexbox-1/images/flex-direction-terms.svg)
 
 Ricorda che l'impostazione di un contenitore flex come riga posiziona gli elementi flex fianco a fianco da sinistra a destra. Un contenitore flex impostato come colonna piazza gli oggetti flex in una pila verticale dall'alto verso il basso. Per ognuno, la direzione in cui sono disposti gli elementi flex è chiamata **asse principale**. Per una riga, si tratta di una linea orizzontale che taglia ogni elemento. E per una colonna, l'asse principale è una linea verticale attraverso gli elementi.
 
diff --git a/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md b/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
index d798f846d2..2aa00ea15d 100644
--- a/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
+++ b/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/access-array-data-with-indexes.md
@@ -25,11 +25,9 @@ const data = array[1];
 
 `console.log(array[0])` scrive `50`, e `data` ha il valore `60`.
 
-**Nota:** Non ci dovrebbero essere spazi tra il nome dell'array e le parentesi quadre, come in `array [0]`. Anche se JavaScript è in grado di elaborarlo correttamente, questo potrebbe confondere altri programmatori che leggono il tuo codice.
-
 # --instructions--
 
-Crea una variabile chiamata `myData` e impostala al primo valore di `myArray` usando la notazione a parentesi.
+Crea una variabile chiamata `myData` e imponila uguale al primo valore di `myArray` usando la notazione a parentesi quadre.
 
 # --hints--
 
@@ -51,7 +49,7 @@ assert(
 );
 ```
 
-Si dovrebbe accedere ai dati nella variabile `myArray` utilizzando la notazione a parentesi.
+Dovresti accedere ai dati nella variabile `myArray` usando la notazione a parentesi quadre.
 
 ```js
 assert(
diff --git a/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/find-the-length-of-a-string.md b/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/find-the-length-of-a-string.md
index e590f6893d..c7ae6c7835 100644
--- a/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/find-the-length-of-a-string.md
+++ b/curriculum/challenges/italian/02-javascript-algorithms-and-data-structures/basic-javascript/find-the-length-of-a-string.md
@@ -15,7 +15,7 @@ Puoi trovare la lunghezza di un valore `String` scrivendo `.length` dopo la vari
 console.log("Alan Peter".length);
 ```
 
-Il valore `10` sarà visualizzato nella console.
+Il valore `10` sarà visualizzato nella console. Nota che è contato anche il carattere spazio tra "Alan" e "Peter".
 
 Ad esempio, se avessimo creato una variabile `const firstName = "Ada"`, potremmo scoprire quanto è lunga la stringa `Ada` utilizzando la proprietà `firstName.length`.
 
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md
new file mode 100644
index 0000000000..8f9b0ad1c5
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md
@@ -0,0 +1,68 @@
+---
+id: 61329d52e5010e08d9b9d66b
+title: Step 4
+challengeType: 0
+dashedName: step-4
+---
+
+# --description--
+
+Un altro elemento `meta` importante per l'accessibilità e la SEO è la definizione `description`. Il valore dell'attributo `content` è usato dai motori di ricerca per dare una descrizione della tua pagina.
+
+Aggiungi un elemento `meta` con l'attributo `name` impostato a `description`, e dagli un attributo `content` utile.
+
+# --hints--
+
+Dovresti aggiungere un nuovo elemento `meta` a `head`.
+
+```js
+assert.equal(document.querySelectorAll('meta').length, 3);
+```
+
+Dovresti dare a `meta` un attributo `name` con valore di `description`.
+
+```js
+assert.exists(document.querySelector('meta[name="description"]'));
+```
+
+Dovresti dare a `meta` un attributo `content`.
+
+```js
+assert.notEmpty(document.querySelector('meta[name="description"]')?.content);
+```
+
+Il valore dell'attributo `content` non deve superare una lunghezza di 165 caratteri. _Questa è la lunghezza massima della descrizione permessa da Google._
+
+```js
+assert.isAtMost(document.querySelector('meta[name="description"]')?.content?.length, 165);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+--fcc-editable-region--
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+--fcc-editable-region--
+  <body>
+
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md
new file mode 100644
index 0000000000..66fd2b90f4
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md
@@ -0,0 +1,63 @@
+---
+id: 6133acc353338c0bba9cb553
+title: Step 5
+challengeType: 0
+dashedName: step-5
+---
+
+# --description--
+
+Infine, nell'elemento `head`, l'elemento `title` è utile ai lettori di schermi per capire il contenuto di una pagina. Inoltre, è una parte importante della _SEO_.
+
+Assegna alla tua pagina un `title` che sia descrittivo e conciso.
+
+# --hints--
+
+Dovresti aggiungere un elemento `title` dentro `head`.
+
+```js
+assert.exists(document.querySelector('head > title'));
+```
+
+Non dovresti avere un `title` più lungo di 60 caratteri.
+
+```js
+assert.isAtMost(document.querySelector('head > title')?.textContent?.length, 60);
+```
+
+Cerca di essere più descrittivo con il tuo elemento `title`. _Suggerimento: Almeno 15 caratteri_
+
+```js
+assert.isAtLeast(document.querySelector('head > title')?.textContent?.length, 15);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+--fcc-editable-region--
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+--fcc-editable-region--
+  <body>
+
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133d11ef548f51f876149e3.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133d11ef548f51f876149e3.md
new file mode 100644
index 0000000000..e5ba472083
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133d11ef548f51f876149e3.md
@@ -0,0 +1,68 @@
+---
+id: 6133d11ef548f51f876149e3
+title: Step 6
+challengeType: 0
+dashedName: step-6
+---
+
+# --description--
+
+La navigazione è una parte fondamentale dell'accessibilità, e i lettori dello schermo si affidano a te per dare struttura alla pagina. Ciò viene realizzato con elementi HTML semantici.
+
+Aggiungi un elemento `header` e un elemento `main` alla tua pagina.
+
+L'elemento `header` verrà utilizzato per introdurre la pagina, oltre a fornire un menù di navigazione.
+
+L'elemento `main` conterrà il contenuto principale della tua pagina.
+
+# --hints--
+
+Dovresti aggiungere un elemento `header` dentro `body`.
+
+```js
+assert.exists(document.querySelector('body > header'));
+```
+
+Dovresti aggiungere un elemento `main` dentro `body`.
+
+```js
+assert.exists(document.querySelector('body > main'));
+```
+
+L'elemento `header` dovrebbe precedere l'elemento `main`.
+
+```js
+assert.exists(document.querySelector('header + main'));
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+--fcc-editable-region--
+  <body>
+
+  </body>
+--fcc-editable-region--
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e2546d0594208229ada50.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e2546d0594208229ada50.md
new file mode 100644
index 0000000000..4428c42d97
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e2546d0594208229ada50.md
@@ -0,0 +1,93 @@
+---
+id: 613e2546d0594208229ada50
+title: Step 7
+challengeType: 0
+dashedName: step-7
+---
+
+# --description--
+
+All'interno dell'elemento `header`, provedi del contesto per la pagina annidando un elemento `img`, `h1`, e `nav`.
+
+L'`img` dovrebbe puntare al link `https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg` e avere un `id` di `logo`.
+
+L'elemento `h1` dovrebbe contenere il testo `HTML/CSS Quiz`.
+
+# --hints--
+
+Dovresti aggiungere un elemento `img` all'elemento `header`.
+
+```js
+assert.exists(document.querySelector('header > img'));
+```
+
+Dovresti aggiungere un elemento `h1` all'elemento `header`.
+
+```js
+assert.exists(document.querySelector('header > h1'));
+```
+
+Dovresti aggiungere un elemento `nav` all'elemento `header`.
+
+```js
+assert.exists(document.querySelector('header > nav'));
+```
+
+Dovresti posizionare gli elementi `img`, `h1` e `nav` in questo ordine.
+
+```js
+assert.exists(document.querySelector('img + h1 + nav'));
+```
+
+Dovresti dare all'elemento `img` un attributo `src` di `https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg`.
+
+```js
+assert.equal(document.querySelector('img')?.src, 'https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg');
+```
+
+Dovresti dare all'elemento `img` un attributo `id` di `logo`.
+
+```js
+assert.equal(document.querySelector('img')?.id, 'logo');
+```
+
+Dovresti dare all'elemento `h1` il testo `HTML/CSS Quiz`.
+
+```js
+assert.include(document.querySelector('h1')?.innerText?.toLowerCase(), 'html/css quiz');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+--fcc-editable-region--
+    <header>
+
+    </header>
+--fcc-editable-region--
+    <main></main>
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e275749ebd008e74bb62e.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e275749ebd008e74bb62e.md
new file mode 100644
index 0000000000..be7166bdd6
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e275749ebd008e74bb62e.md
@@ -0,0 +1,66 @@
+---
+id: 613e275749ebd008e74bb62e
+title: Step 8
+challengeType: 0
+dashedName: step-8
+---
+
+# --description--
+
+Una proprietà utile di un _SVG_ (scalable vector graphics - grafica vettoriale scalabile) è che contiene un attributo `path` che permette di scalare l'immagine senza influenzare la risoluzione dell'immagine risultante.
+
+Attualmente, l'elemento `img` sta assumendo la sua dimensione predefinita, che è troppo grande. Ridimensiona l'immagine correttamente usando il suo `id` come selettore e impostando `width` a `max(100px, 18vw)`.
+
+# --hints--
+
+Dovresti usare il selettore `#logo` per selezionare l'elemento `img`.
+
+```js
+assert.exists(new __helpers.CSSHelp(document).getStyle('#logo'));
+```
+
+Dovresti dare a `img` un `width` di `max(100px, 18vw)`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('#logo')?.width, 'max(100px, 18vw)');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+    <header>
+      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
+      <h1>HTML/CSS Quiz</h1>
+      <nav></nav>
+    </header>
+    <main></main>
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+
+--fcc-editable-region--
+
+--fcc-editable-region--
+
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61408e4ae3e35d08feb260eb.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61408e4ae3e35d08feb260eb.md
new file mode 100644
index 0000000000..8a7ff94bba
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61408e4ae3e35d08feb260eb.md
@@ -0,0 +1,83 @@
+---
+id: 61408e4ae3e35d08feb260eb
+title: Step 11
+challengeType: 0
+dashedName: step-11
+---
+
+# --description--
+
+Cambia il colore del font di `h1` a `#f1be32`, e imposta la dimensione del font a `min(5vw, 1.2em)`.
+
+# --hints--
+
+Dovresti usare il selettore di elemento `h1`.
+
+```js
+assert.exists(new __helpers.CSSHelp(document).getStyle('h1'));
+```
+
+Dovresti dare a `h1` un `color` di `#f1be32`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('h1')?.color, 'rgb(241, 190, 50)');
+```
+
+Dovresti dare a `h1` un `font-size` di `min(5vw, 1.2em)`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('h1')?.fontSize, 'min(5vw, 1.2em)');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+    <header>
+      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
+      <h1>HTML/CSS Quiz</h1>
+      <nav></nav>
+    </header>
+    <main></main>
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+
+header {
+  width: 100%;
+    height: 50px;
+    background-color: #1b1b32;
+    display: flex;
+}
+
+#logo {
+  width: max(100px, 18vw);
+    background-color: #0a0a23;
+  aspect-ratio: 35 / 4;
+    padding: 0.4rem;
+}
+
+--fcc-editable-region--
+
+--fcc-editable-region--
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61408f155e798909b6908712.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61408f155e798909b6908712.md
new file mode 100644
index 0000000000..a761ba3628
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61408f155e798909b6908712.md
@@ -0,0 +1,112 @@
+---
+id: 61408f155e798909b6908712
+title: Step 12
+challengeType: 0
+dashedName: step-12
+---
+
+# --description--
+
+Per abilitare la navigazione sulla pagina, aggiungi un elenco puntato con i tre seguenti elementi:
+
+- `INFO`
+- `HTML`
+- `CSS`
+
+Il testo degli elementi della lista dovrebbe essere racchiuso in tag ancora.
+
+# --hints--
+
+Dovresti annidare un elemento `ul` dentro `nav`.
+
+```js
+assert.equal(document.querySelectorAll('nav > ul')?.length, 1);
+```
+
+Dovresti annidare tre elementi `li` dentro l'elemento `ul`.
+
+```js
+assert.equal(document.querySelectorAll('nav > ul > li')?.length, 3);
+```
+
+Dovresti annidare un elemento `a` dentro ogni elemento `li`.
+
+```js
+assert.equal(document.querySelectorAll('nav > ul > li > a')?.length, 3);
+```
+
+Dovresti dare al tuo primo elemento `a` il testo `INFO`.
+
+```js
+assert.equal(document.querySelectorAll('nav > ul > li > a')?.[0]?.textContent, 'INFO');
+```
+
+Dovresti dare al tuo secondo elemento `a` il testo `HTML`.
+
+```js
+assert.equal(document.querySelectorAll('nav > ul > li > a')?.[1]?.textContent, 'HTML');
+```
+
+Dovresti dare al tuo terzo elemento `a` un testo `CSS`.
+
+```js
+assert.equal(document.querySelectorAll('nav > ul > li > a')?.[2]?.textContent, 'CSS');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+    <header>
+      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
+      <h1>HTML/CSS Quiz</h1>
+--fcc-editable-region--
+      <nav>
+
+      </nav>
+--fcc-editable-region--
+    </header>
+    <main></main>
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+
+header {
+  width: 100%;
+    height: 50px;
+    background-color: #1b1b32;
+    display: flex;
+}
+
+#logo {
+  width: max(100px, 18vw);
+    background-color: #0a0a23;
+  aspect-ratio: 35 / 4;
+    padding: 0.4rem;
+}
+
+h1 {
+  color: #f1be32;
+    font-size: min(5vw, 1.2em);
+}
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61435e3c0679a306c20f1acc.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61435e3c0679a306c20f1acc.md
new file mode 100644
index 0000000000..ff16094ab5
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61435e3c0679a306c20f1acc.md
@@ -0,0 +1,125 @@
+---
+id: 61435e3c0679a306c20f1acc
+title: Step 18
+challengeType: 0
+dashedName: step-18
+---
+
+# --description--
+
+Per poter navigare dentro la pagina, dai ad ogni elemento ancora un `href` corrispondente all'`id` degli elementi `h2`.
+
+# --hints--
+
+Dovresti dare al primo elemento `a` un `href` di `#student-info`.
+
+```js
+assert.equal(document.querySelectorAll('a')?.[0]?.getAttribute('href'), '#student-info');
+```
+
+Dovresti dare al tuo secondo elemento `a` un `href` di `#html-questions`.
+
+```js
+assert.equal(document.querySelectorAll('a')?.[1]?.getAttribute('href'), '#html-questions');
+```
+
+Dovresti dare al tuo terzo elemento `a` un `href` di `#css-questions`.
+
+```js
+assert.equal(document.querySelectorAll('a')?.[2]?.getAttribute('href'), '#css-questions');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+    <header>
+      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
+      <h1>HTML/CSS Quiz</h1>
+      <nav>
+--fcc-editable-region--
+        <ul>
+          <li><a>INFO</a></li>
+          <li><a>HTML</a></li>
+          <li><a>CSS</a></li>
+              </ul>
+--fcc-editable-region--
+      </nav>
+    </header>
+    <main>
+      <form method="post" action="https://freecodecamp.org/practice-project/accessibility-quiz">
+        <section role="region" aria-labelledby="student-info">
+          <h2 id="student-info">Student Info</h2>
+        </section>
+        <section role="region" aria-labelledby="html-questions">
+          <h2 id="html-questions">HTML</h2>
+        </section>
+        <section role="region" aria-labelledby="css-questions">
+          <h2 id="css-questions">CSS</h2>
+        </section>
+      </form>
+    </main>
+  </body>
+</html>
+
+```
+
+```css
+body {
+  background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+
+header {
+  width: 100%;
+    height: 50px;
+    background-color: #1b1b32;
+    display: flex;
+}
+
+#logo {
+  width: max(100px, 18vw);
+    background-color: #0a0a23;
+  aspect-ratio: 35 / 4;
+    padding: 0.4rem;
+}
+
+h1 {
+  color: #f1be32;
+    font-size: min(5vw, 1.2em);
+}
+
+nav {
+  width: 50%;
+    max-width: 300px;
+    height: 50px;
+}
+
+nav > ul {
+  display: flex;
+    justify-content: space-evenly;
+}
+
+h1,
+h2 {
+    font-family: Verdana, Tahoma;
+}
+
+h2 {
+    border-bottom: 4px solid #dfdfe2;
+}
+
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61487b77d4a37707073a64e5.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61487b77d4a37707073a64e5.md
new file mode 100644
index 0000000000..aa61cc66d2
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61487b77d4a37707073a64e5.md
@@ -0,0 +1,261 @@
+---
+id: 61487b77d4a37707073a64e5
+title: Step 48
+challengeType: 0
+dashedName: step-48
+---
+
+# --description--
+
+Quando la larghezza dello schermo è piccola, l'elemento `h1` non si mette su più righe come dovrebbe. Allinea al centro il testo di `h1`.
+
+Poi, dai a `main` un padding che renda completamente visibile l'intestazione di sezione `Student Info`.
+
+# --hints--
+
+Dovresti dare ad `h1` un `text-align` di `center`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('h1')?.textAlign, 'center');
+```
+
+Dovresti aggiungere un selettore `main` per selezionare l'elemento `main`.
+
+```js
+assert.exists(new __helpers.CSSHelp(document).getStyle('main'));
+```
+
+Dovresti dare a `main` un `padding-top` di almeno `25px`.
+
+```js
+assert.isAtLeast(Number(new __helpers.CSSHelp(document).getStyle('main')?.paddingTop?.replace(/\D+/, '')), 25);
+```
+
+Dovresti cambiare solo il valore di `padding-top`.
+
+```js
+assert.isEmpty(new __helpers.CSSHelp(document).getStyle('main')?.paddingBottom);
+assert.isEmpty(new __helpers.CSSHelp(document).getStyle('main')?.paddingLeft);
+assert.isEmpty(new __helpers.CSSHelp(document).getStyle('main')?.paddingRight);
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+    <header>
+      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
+      <h1>HTML/CSS Quiz</h1>
+      <nav>
+        <ul>
+          <li><a href="#student-info">INFO</a></li>
+          <li><a href="#html-questions">HTML</a></li>
+          <li><a href="#css-questions">CSS</a></li>
+              </ul>
+      </nav>
+    </header>
+    <main>
+      <form method="post" action="https://freecodecamp.org/practice-project/accessibility-quiz">
+        <section role="region" aria-labelledby="student-info">
+          <h2 id="student-info">Student Info</h2>
+          <div class="info">
+            <label for="student-name">Name:</label>
+            <input type="text" name="student-name" id="student-name" />
+          </div>
+          <div class="info">
+            <label for="student-email">Email:</label>
+            <input type="email" name="student-email" id="student-email" />
+          </div>
+          <div class="info">
+            <label for="birth-date">D.O.B.<span class="sr-only">(Date of Birth)</span></label>
+            <input type="date" name="birth-date" id="birth-date" />
+          </div>
+        </section>
+        <section role="region" aria-labelledby="html-questions">
+          <h2 id="html-questions">HTML</h2>
+          <div class="question-block">
+            <p>1</p>
+            <fieldset class="question" name="html-question-one">
+              <legend>
+                The legend element represents a caption for the content of its
+                parent fieldset element
+              </legend>
+              <ul class="answers-list">
+                <li>
+                  <label for="q1-a1">
+                    <input type="radio" id="q1-a1" name="q1" value="true" />
+                    True
+                  </label>
+                </li>
+                <li>
+                  <label for="q1-a2">
+                    <input type="radio" id="q1-a2" name="q1" value="false" />
+                    False
+                  </label>
+                </li>
+              </ul>
+            </fieldset>
+          </div>
+          <div class="question-block">
+            <p>2</p>
+            <fieldset class="question" name="html-question-two">
+              <legend>
+                A label element nesting an input element is required to have a
+                for attribute with the same value as the input's id
+              </legend>
+              <ul class="answers-list">
+                <li>
+                  <label for="q2-a1">
+                    <input type="radio" id="q2-a1" name="q2" value="true" />
+                    True
+                  </label>
+                </li>
+                <li>
+                  <label for="q2-a2">
+                    <input type="radio" id="q2-a2" name="q2" value="false" />
+                    False
+                  </label>
+                </li>
+              </ul>
+            </fieldset>
+          </div>
+        </section>
+        <section role="region" aria-labelledby="css-questions">
+          <h2 id="css-questions">CSS</h2>
+          <div class="formrow">
+            <div class="question-block">
+              <label for="customer">Are you a frontend developer?</label>
+            </div>
+            <div class="answer">
+              <select name="customer" id="customer" required>
+                <option value="">Select an option</option>
+                <option value="yes">Yes</option>
+                <option value="no">No</option>
+              </select>
+            </div>
+            <div class="question-block">
+              <label for="css-questions">Do you have any questions:</label>
+            </div>
+            <div class="answer">
+              <textarea id="css-questions" name="css-questions" rows="5" cols="24" placeholder="Who is flexbox..."></textarea>
+            </div>
+          </div>
+        </section>
+        <button type="submit">Submit</button>
+      </form>
+    </main>
+    <footer>
+      <address>
+        <a href="https://freecodecamp.org">freeCodeCamp</a><br />
+        San Francisco<br />
+        California<br />
+        USA
+      </address>
+    </footer>
+  </body>
+</html>
+
+```
+
+```css
+body {
+  background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+
+header {
+  width: 100%;
+    height: 50px;
+    background-color: #1b1b32;
+    display: flex;
+  justify-content: space-between;
+  align-items: center;
+  position: fixed;
+  top: 0;
+}
+
+#logo {
+  width: max(100px, 18vw);
+    background-color: #0a0a23;
+  aspect-ratio: 35 / 4;
+    padding: 0.4rem;
+}
+
+--fcc-editable-region--
+h1 {
+  color: #f1be32;
+    font-size: min(5vw, 1.2em);
+
+}
+
+
+--fcc-editable-region--
+
+nav {
+  width: 50%;
+    max-width: 300px;
+    height: 50px;
+}
+
+nav > ul {
+  display: flex;
+    justify-content: space-evenly;
+}
+
+nav > ul > li {
+  color: #dfdfe2;
+  margin: 0 0.2rem;
+    padding: 0.2rem;
+    display: block;
+}
+
+nav > ul > li:hover {
+  background-color: #dfdfe2;
+  color: #1b1b32;
+  cursor: pointer;
+}
+
+li > a {
+  color: inherit;
+  text-decoration: none;
+}
+
+h1,
+h2 {
+  font-family: Verdana, Tahoma;
+}
+
+h2 {
+  border-bottom: 4px solid #dfdfe2;
+}
+
+p::before {
+  content: "Question #";
+}
+
+.sr-only {
+  position: absolute;
+    width: 1px;
+    height: 1px;
+    padding: 0;
+    margin: -1px;
+    overflow: hidden;
+    clip: rect(0, 0, 0, 0);
+    white-space: nowrap;
+    border: 0;
+}
+
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61487da611a65307e78d2c20.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61487da611a65307e78d2c20.md
new file mode 100644
index 0000000000..35c4cdb6e0
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61487da611a65307e78d2c20.md
@@ -0,0 +1,275 @@
+---
+id: 61487da611a65307e78d2c20
+title: Step 49
+challengeType: 0
+dashedName: step-49
+---
+
+# --description--
+
+Su schermi piccoli, l'elenco puntato nella barra di navigazione va oltre il lato destro dello schermo.
+
+Sistemalo usando _Flexbox_ per portare su più righe il contenuto di `ul`. Poi, imposta le seguenti proprietà CSS per allineare correttamente il testo:
+
+```css
+align-items: center;
+padding-inline-start: 0;
+margin-block: 0;
+height: 100%;
+```
+
+# --hints--
+
+Dovresti dare a `ul` un `flex-wrap` di `wrap`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('nav > ul')?.flexWrap, 'wrap');
+```
+
+Dovresti dare a `ul` un `align-items` di `center`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('nav > ul')?.alignItems, 'center');
+```
+
+Dovresti dare a `ul` un `padding-inline-start` di `0`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('nav > ul')?.paddingInlineStart, '0px');
+```
+
+Dovresti dare a `ul` un `margin-block` di `0`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('nav > ul')?.marginBlock, '0px');
+```
+
+Dovresti dare a `ul` un `height` di `100%`.
+
+```js
+assert.equal(new __helpers.CSSHelp(document).getStyle('nav > ul')?.height, '100%');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+    <header>
+      <img id="logo" src="https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg">
+      <h1>HTML/CSS Quiz</h1>
+      <nav>
+        <ul>
+          <li><a href="#student-info">INFO</a></li>
+          <li><a href="#html-questions">HTML</a></li>
+          <li><a href="#css-questions">CSS</a></li>
+              </ul>
+      </nav>
+    </header>
+    <main>
+      <form method="post" action="https://freecodecamp.org/practice-project/accessibility-quiz">
+        <section role="region" aria-labelledby="student-info">
+          <h2 id="student-info">Student Info</h2>
+          <div class="info">
+            <label for="student-name">Name:</label>
+            <input type="text" name="student-name" id="student-name" />
+          </div>
+          <div class="info">
+            <label for="student-email">Email:</label>
+            <input type="email" name="student-email" id="student-email" />
+          </div>
+          <div class="info">
+            <label for="birth-date">D.O.B.<span class="sr-only">(Date of Birth)</span></label>
+            <input type="date" name="birth-date" id="birth-date" />
+          </div>
+        </section>
+        <section role="region" aria-labelledby="html-questions">
+          <h2 id="html-questions">HTML</h2>
+          <div class="question-block">
+            <p>1</p>
+            <fieldset class="question" name="html-question-one">
+              <legend>
+                The legend element represents a caption for the content of its
+                parent fieldset element
+              </legend>
+              <ul class="answers-list">
+                <li>
+                  <label for="q1-a1">
+                    <input type="radio" id="q1-a1" name="q1" value="true" />
+                    True
+                  </label>
+                </li>
+                <li>
+                  <label for="q1-a2">
+                    <input type="radio" id="q1-a2" name="q1" value="false" />
+                    False
+                  </label>
+                </li>
+              </ul>
+            </fieldset>
+          </div>
+          <div class="question-block">
+            <p>2</p>
+            <fieldset class="question" name="html-question-two">
+              <legend>
+                A label element nesting an input element is required to have a
+                for attribute with the same value as the input's id
+              </legend>
+              <ul class="answers-list">
+                <li>
+                  <label for="q2-a1">
+                    <input type="radio" id="q2-a1" name="q2" value="true" />
+                    True
+                  </label>
+                </li>
+                <li>
+                  <label for="q2-a2">
+                    <input type="radio" id="q2-a2" name="q2" value="false" />
+                    False
+                  </label>
+                </li>
+              </ul>
+            </fieldset>
+          </div>
+        </section>
+        <section role="region" aria-labelledby="css-questions">
+          <h2 id="css-questions">CSS</h2>
+          <div class="formrow">
+            <div class="question-block">
+              <label for="customer">Are you a frontend developer?</label>
+            </div>
+            <div class="answer">
+              <select name="customer" id="customer" required>
+                <option value="">Select an option</option>
+                <option value="yes">Yes</option>
+                <option value="no">No</option>
+              </select>
+            </div>
+            <div class="question-block">
+              <label for="css-questions">Do you have any questions:</label>
+            </div>
+            <div class="answer">
+              <textarea id="css-questions" name="css-questions" rows="5" cols="24" placeholder="Who is flexbox..."></textarea>
+            </div>
+          </div>
+        </section>
+        <button type="submit">Submit</button>
+      </form>
+    </main>
+    <footer>
+      <address>
+        <a href="https://freecodecamp.org">freeCodeCamp</a><br />
+        San Francisco<br />
+        California<br />
+        USA
+      </address>
+    </footer>
+  </body>
+</html>
+
+```
+
+```css
+body {
+  background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+
+header {
+  width: 100%;
+    height: 50px;
+    background-color: #1b1b32;
+    display: flex;
+  justify-content: space-between;
+  align-items: center;
+  position: fixed;
+  top: 0;
+}
+
+#logo {
+  width: max(100px, 18vw);
+    background-color: #0a0a23;
+  aspect-ratio: 35 / 4;
+    padding: 0.4rem;
+}
+
+h1 {
+  color: #f1be32;
+    font-size: min(5vw, 1.2em);
+  text-align: center;
+}
+
+nav {
+  width: 50%;
+    max-width: 300px;
+    height: 50px;
+}
+
+--fcc-editable-region--
+nav > ul {
+  display: flex;
+    justify-content: space-evenly;
+
+}
+--fcc-editable-region--
+
+nav > ul > li {
+  color: #dfdfe2;
+  margin: 0 0.2rem;
+    padding: 0.2rem;
+    display: block;
+}
+
+nav > ul > li:hover {
+  background-color: #dfdfe2;
+  color: #1b1b32;
+  cursor: pointer;
+}
+
+li > a {
+  color: inherit;
+  text-decoration: none;
+}
+
+main {
+  padding-top: 50px;
+}
+
+h1,
+h2 {
+  font-family: Verdana, Tahoma;
+}
+
+h2 {
+  border-bottom: 4px solid #dfdfe2;
+}
+
+p::before {
+  content: "Question #";
+}
+
+.sr-only {
+  position: absolute;
+    width: 1px;
+    height: 1px;
+    padding: 0;
+    margin: -1px;
+    overflow: hidden;
+    clip: rect(0, 0, 0, 0);
+    white-space: nowrap;
+    border: 0;
+}
+
+```
diff --git a/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md
new file mode 100644
index 0000000000..8d7c25f124
--- /dev/null
+++ b/curriculum/challenges/italian/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md
@@ -0,0 +1,50 @@
+---
+id: 614ccc21ea91ef1736b9b578
+title: Step 1
+challengeType: 0
+dashedName: step-1
+---
+
+# --description--
+
+Benvenuto alla prima parte del Quiz sull'Accessibilità. Adesso che stai diventando uno sviluppatore esperto di HTML e CSS, abbiamo già scritto il boilerplate base.
+
+Inizia questo viaggio nell'accessibilità fornendo un attributo `lang` al tuo elemento `html`. Questo aiuterà i lettori di schermo a identificare la lingua della pagina.
+
+# --hints--
+
+Dovresti dare all'elemento `html` un attributo `lang`. _Suggerimento: Puoi usare il valore `en` per l'inglese._
+
+```js
+assert.match(code, /<html\s+lang=('|")[\w\-]+?\1\s*>/i);
+// TODO: This should/could be fixed in the builder.js
+// assert.notThrow(Intl.getCanonicalLocales(document.querySelector('html').lang));
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+--fcc-editable-region--
+<html>
+  <head>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+
+  </body>
+</html>
+--fcc-editable-region--
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613297a923965e0703b64796.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613297a923965e0703b64796.md
index 61fdc659b3..e5010479ca 100644
--- a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613297a923965e0703b64796.md
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613297a923965e0703b64796.md
@@ -1,6 +1,6 @@
 ---
 id: 613297a923965e0703b64796
-title: Etapa 2
+title: Passo 2
 challengeType: 0
 dashedName: step-2
 ---
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329b210dac0b08047fd6ab.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329b210dac0b08047fd6ab.md
index 7ed19a582a..3854c712a2 100644
--- a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329b210dac0b08047fd6ab.md
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329b210dac0b08047fd6ab.md
@@ -1,6 +1,6 @@
 ---
 id: 61329b210dac0b08047fd6ab
-title: Etapa 3
+title: Passo 3
 challengeType: 0
 dashedName: step-3
 ---
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md
index 11c83a9c29..6cee7ea90d 100644
--- a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/61329d52e5010e08d9b9d66b.md
@@ -1,6 +1,6 @@
 ---
 id: 61329d52e5010e08d9b9d66b
-title: Etapa 4
+title: Passo 4
 challengeType: 0
 dashedName: step-4
 ---
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md
index b2121f0bbe..d22d9ff913 100644
--- a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133acc353338c0bba9cb553.md
@@ -1,6 +1,6 @@
 ---
 id: 6133acc353338c0bba9cb553
-title: Etapa 5
+title: Passo 5
 challengeType: 0
 dashedName: step-5
 ---
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133d11ef548f51f876149e3.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133d11ef548f51f876149e3.md
new file mode 100644
index 0000000000..3b5d73c778
--- /dev/null
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/6133d11ef548f51f876149e3.md
@@ -0,0 +1,68 @@
+---
+id: 6133d11ef548f51f876149e3
+title: Passo 6
+challengeType: 0
+dashedName: step-6
+---
+
+# --description--
+
+A navegação é uma parte fundamental da acessibilidade. Os leitores de tela dependem de você para fornecer a estrutura de sua página. Isso é feito com elementos HTML semânticos.
+
+Adicione um elemento `header` e um elemento `main` à sua página.
+
+O elemento `header` será usado para introduzir a página, bem como fornecer um menu de navegação.
+
+O elemento `main` contém o conteúdo principal de sua página.
+
+# --hints--
+
+Você deve adicionar um elemento `header` ao `body`.
+
+```js
+assert.exists(document.querySelector('body > header'));
+```
+
+Você deve adicionar um novo elemento `main` ao `body`.
+
+```js
+assert.exists(document.querySelector('body > main'));
+```
+
+O elemento `header` deve vir antes do elemento `main`.
+
+```js
+assert.exists(document.querySelector('header + main'));
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+--fcc-editable-region--
+  <body>
+
+  </body>
+--fcc-editable-region--
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e2546d0594208229ada50.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e2546d0594208229ada50.md
new file mode 100644
index 0000000000..7bbf2f95e8
--- /dev/null
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/613e2546d0594208229ada50.md
@@ -0,0 +1,93 @@
+---
+id: 613e2546d0594208229ada50
+title: Passo 7
+challengeType: 0
+dashedName: step-7
+---
+
+# --description--
+
+No `header`, forneça um contexto sobre a página, aninhando um elemento `img`, um `h1` e um `nav`.
+
+A `img` deve apontar para `https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg` e ter no `id` o valor `logo`.
+
+O `h1` deve conter o texto `HTML/CSS Quiz`.
+
+# --hints--
+
+Você deve adicionar um elemento `img` ao elemento `header`.
+
+```js
+assert.exists(document.querySelector('header > img'));
+```
+
+Você deve adicionar um elemento `h1` ao elemento `header`.
+
+```js
+assert.exists(document.querySelector('header > h1'));
+```
+
+Você deve adicionar um elemento `nav` ao elemento `header`.
+
+```js
+assert.exists(document.querySelector('header > nav'));
+```
+
+Você deve colocar os elementos `img`, `h1` e `nav` nessa ordem.
+
+```js
+assert.exists(document.querySelector('img + h1 + nav'));
+```
+
+Você deve dar ao elemento `img` um atributo `src` equivalente a `https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg`.
+
+```js
+assert.equal(document.querySelector('img')?.src, 'https://cdn.freecodecamp.org/platform/universal/fcc_primary.svg');
+```
+
+Você deve dar ao elemento `img` um atributo `id` equivalente a `logo`.
+
+```js
+assert.equal(document.querySelector('img')?.id, 'logo');
+```
+
+Você deve atribuir ao elemento `h1` o texto `HTML/CSS Quiz`.
+
+```js
+assert.include(document.querySelector('h1')?.innerText?.toLowerCase(), 'html/css quiz');
+```
+
+# --seed--
+
+## --seed-contents--
+
+```html
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta name="description" content="freeCodeCamp Accessibility Quiz practice project" />
+    <title>Accessibility Quiz</title>
+    <link rel="stylesheet" href="styles.css" />
+  </head>
+  <body>
+--fcc-editable-region--
+    <header>
+
+    </header>
+--fcc-editable-region--
+    <main></main>
+  </body>
+</html>
+
+```
+
+```css
+body {
+    background: #f5f6f7;
+    color: #1b1b32;
+    font-family: Helvetica;
+    margin: 0;
+}
+```
diff --git a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md
index 934f625280..903aa5543b 100644
--- a/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md
+++ b/curriculum/challenges/portuguese/14-responsive-web-design-22/learn-accessibility-by-building-a-quiz/614ccc21ea91ef1736b9b578.md
@@ -1,6 +1,6 @@
 ---
 id: 614ccc21ea91ef1736b9b578
-title: Etapa 1
+title: Passo 1
 challengeType: 0
 dashedName: step-1
 ---
diff --git a/curriculum/challenges/ukrainian/01-responsive-web-design/applied-visual-design/set-the-font-size-for-multiple-heading-elements.md b/curriculum/challenges/ukrainian/01-responsive-web-design/applied-visual-design/set-the-font-size-for-multiple-heading-elements.md
index 4396541573..6040d1fecb 100644
--- a/curriculum/challenges/ukrainian/01-responsive-web-design/applied-visual-design/set-the-font-size-for-multiple-heading-elements.md
+++ b/curriculum/challenges/ukrainian/01-responsive-web-design/applied-visual-design/set-the-font-size-for-multiple-heading-elements.md
@@ -11,7 +11,9 @@ dashedName: set-the-font-size-for-multiple-heading-elements
 
 Властивість `font-size` використовується для визначення розміру тексту в заданому елементі. Це правило можна застосовувати для кількох елементів, щоб створити візуальну узгодженість тексту на сторінці. У цьому завданні ви встановите значення для всіх `h1` по `h6` тегів, щоб вирівняти розмір заголовків.
 
-# --instructions-- <p>У тегах <code>style</code>, встановіть <code>font-size</code> у:</p>
+# --instructions--
+
+  <p>У тегах <code>style</code>, встановіть <code>font-size</code> у:</p>
 
   <ul>
     <li>Тег <code>h1</code> до 68px.</li>
diff --git a/curriculum/challenges/ukrainian/02-javascript-algorithms-and-data-structures/regular-expressions/positive-and-negative-lookahead.md b/curriculum/challenges/ukrainian/02-javascript-algorithms-and-data-structures/regular-expressions/positive-and-negative-lookahead.md
index 61025dd49c..15745ff2dd 100644
--- a/curriculum/challenges/ukrainian/02-javascript-algorithms-and-data-structures/regular-expressions/positive-and-negative-lookahead.md
+++ b/curriculum/challenges/ukrainian/02-javascript-algorithms-and-data-structures/regular-expressions/positive-and-negative-lookahead.md
@@ -14,7 +14,7 @@ dashedName: positive-and-negative-lookahead
 
 Позитивне передбачення шукатиме, щоб переконатися, що елемент у шаблоні пошуку є, але насправді не відповідатиме йому. Позитивне передбачення використовується як `(?=...)`, де `...` необхідна частина, яка не збігається.
 
-З іншого боку, негативне передбачення буде стежити за тим, щоб елемент в зразку пошуку був відсутній. Негативне передбачення використовується як `(?=...)`, де `...` необхідний шаблон, який не збігається. Решта шаблону повертається, якщо немає негативного передбачення.
+З іншого боку, негативне передбачення буде стежити за тим, щоб елемент в зразку пошуку був відсутній. Негативний огляд використовується як `(?!...)`, де `...` необхідний шаблон, який не збігається. Решта шаблону повертається, якщо немає негативного передбачення.
 
 Lookaheads є трохи заплутаними, але деякі приклади допоможуть вам в цьому.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-101-optimum-polynomial.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-101-optimum-polynomial.md
index 8affe9ba91..949efa42ca 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-101-optimum-polynomial.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-101-optimum-polynomial.md
@@ -20,7 +20,9 @@ dashedName: problem-101-optimum-polynomial
 
 Звідси отримуємо такі оптимальні многочлени для кубічної послідовності:
 
-$$\begin{array}{ll} OP(1, n) = 1          & 1, {\color{red}1}, 1, 1, \ldots     \\\\ OP(2, n) = 7n−6       & 1, 8, {\color{red}{15}}, \ldots     \\\\ OP(3, n) = 6n^2−11n+6 & 1, 8, 27, {\color{red}{58}}, \ldots \\\\ OP(4, n) = n^3        & 1, 8, 27, 64, 125, \ldots \end{array}$$
+$$\begin{array}{ll}   OP(1, n) = 1          & 1, {\color{red}1}, 1, 1, \ldots     \\\\
+  OP(2, n) = 7n−6       & 1, 8, {\color{red}{15}}, \ldots     \\\\   OP(3, n) = 6n^2−11n+6 & 1, 8, 27, {\color{red}{58}}, \ldots \\\\
+  OP(4, n) = n^3        & 1, 8, 27, 64, 125, \ldots \end{array}$$
 
 Очевидно, не існує BOP для k ≥ 4. Враховуючи суму перших неправильних членів, створених поганими оптимальними многочленами (зазначені у $\color{red}{red}$ вище), отримуємо 1 + 15 + 58 = 74. Розгляньмо твірну функцію для многочлена десятого степеня:
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-103-special-subset-sums-optimum.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-103-special-subset-sums-optimum.md
index 9b8f6d63b5..7d4c88dacd 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-103-special-subset-sums-optimum.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-103-special-subset-sums-optimum.md
@@ -15,7 +15,10 @@ dashedName: problem-103-special-subset-sums-optimum
 
 Якщо $S(A)$ обмежене даним n, назвемо його оптимальним набором особливих сум. Перші п'ять оптимальних особливих сум наведені нижче.
 
-$\begin{align} & n = 1: \\{1\\} \\\\ & n = 2: \\{1, 2\\} \\ & n = 3: \\{2, 3, 3, 4\\} \\\\ & n = 4: \\{3, 5, 6, 7\\} \\\\ & n = 5: \\{6, 9, 11, 12, 13\\} \\\\ \end{align}$$
+$\begin{align}   & n = 1: \\{1\\} \\\\
+  & n = 2: \\{1, 2\\} \\   & n = 3: \\{2, 3, 3, 4\\} \\\\
+  & n = 4: \\{3, 5, 6, 7\\} \\\\   & n = 5: \\{6, 9, 11, 12, 13\\} \\\\
+\end{align}$$
 
 Здається, що для даного оптимального набору $A = \\{a_1, a_2, \ldots, a_n\\}$, наступний оптимальний набір у вигляді $B = \\{b, a_1 + b, a_2 + b, \ldots, a_n + b\\}$, де b - середній елемент з попереднього рядка.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-108-diophantine-reciprocals-i.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-108-diophantine-reciprocals-i.md
index ad301a8890..40a47c14c9 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-108-diophantine-reciprocals-i.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-108-diophantine-reciprocals-i.md
@@ -14,7 +14,9 @@ $$\frac{1}{x} + \frac{{1}{y} = \frac{1}{n}$$
 
 Для `n` = 4 існує три різних рішення:
 
-$$\begin{align} & \frac{1}{5} + \frac{1}{20} = \frac{1}{4}\\\\ \\\\ & \frac{1}{6} + \frac{1}{12} = \frac{1}{4}\\\\ \\\\ & \frac{1}{8} + \frac{1}{8} = \frac{1}{4} \end{align}$$
+$$\begin{align}   & \frac{1}{5} + \frac{1}{20} = \frac{1}{4}\\\\
+  \\\\   & \frac{1}{6} + \frac{1}{12} = \frac{1}{4}\\\\
+  \\\\ & \frac{1}{8} + \frac{1}{8} = \frac{1}{4} \end{align}$$
 
 Яке найменше значення `n`, для якого кількість рішень перевищує тисячу?
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-109-darts.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-109-darts.md
index 91c818ee5f..babdcddee7 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-109-darts.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-109-darts.md
@@ -20,7 +20,12 @@ dashedName: problem-109-darts
 
 "Чекаут" – коли гравець може завершити гру при поточному рахунку; найвищий чекаут – 170: T20 T25 D25 (два попадання у потрійне 20 та в яблучко). Існує одинадцять різних варіантів чекауту при рахунку 6:
 
-$$\початок{array} \text{D3} &    &    \\\\ D1        & D2 &    \\\\ S2        & D2 &    \\\\ D2        & D1 &    \\\\ S4        & D1 &    \\\\ S1        & S1 & D2 \\\\ S1        & T1 & D1 \\\\ S1        & S3 & D1 \\\\ D1        & D1 & D1 \\\\ D1        & S2 & D1 \\\\ S2        & S2 & D1 \кінець{array}$$
+$$\початок{array}   \text{D3} &    &    \\\\
+  D1        & D2 &    \\\\   S2        & D2 &    \\\\
+  D2        & D1 &    \\\\   S4        & D1 &    \\\\
+  S1        & S1 & D2 \\\\   S1        & T1 & D1 \\\\
+  S1        & S3 & D1 \\\\   D1        & D1 & D1 \\\\
+  D1        & S2 & D1 \\\\ S2        & S2 & D1 \кінець{array}$$
 
 Зверніть увагу, що D1 D2 відрізняється від D2 D1, оскільки вони закінчуються різними подвоєннями. Однак, комбінація S1 T1 D1 вважається такою ж, як і T1 S1 D1. До того ж, не потрібно вказувати промахи у комбінаціях; наприклад, D3 це те саме, що й 0 D3 і 0 0 D3. Неймовірно, що загалом існує 42336 різних способів чекауту. Скільки різних способів чекауту має гравець з балом меншим за 100?
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-122-efficient-exponentiation.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-122-efficient-exponentiation.md
index f3723dfd77..b998c64170 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-122-efficient-exponentiation.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-122-efficient-exponentiation.md
@@ -14,11 +14,16 @@ $$n × n × \ldots × n = n^{15}$$
 
 Якщо скористатися "двійковим" методом, можна обчислити, виконавши 6 множень:
 
-$$\begin{align} & n × n = n^2\\\\ & n^2 × n^2 = n^4\\\\ & n^4 × n^4 = n^8\\\\ & n^8 × n^4 = n^{12}\\\\ & n^{12} × n^2 = n^{14}\\\\ & n^{14} × n = n^{15} \end{align}$$
+$$\begin{align}   & n × n = n^2\\\\
+  & n^2 × n^2 = n^4\\\\   & n^4 × n^4 = n^8\\\\
+  & n^8 × n^4 = n^{12}\\\\   & n^{12} × n^2 = n^{14}\\\\
+  & n^{14} × n = n^{15} \end{align}$$
 
 Проте кількість множень ще можна зменшити до 5:
 
-$$\begin{align} & n × n = n^2\\\\ & n^2 × n = n^3\\\\ & n^3 × n^3 = n^6\\\\ & n^6 × n^6 = n^{12}\\\\ & n^{12} × n^3 = n^{15} \end{align}$$
+$$\begin{align}   & n × n = n^2\\\\
+  & n^2 × n = n^3\\\\   & n^3 × n^3 = n^6\\\\
+  & n^6 × n^6 = n^{12}\\\\ & n^{12} × n^3 = n^{15} \end{align}$$
 
 Визначаємо $m(k)$ як мінімальну кількість множень для обчислення $n^k$. Наприклад, $m(15) = 5$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-137-fibonacci-golden-nuggets.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-137-fibonacci-golden-nuggets.md
index 978fcd6356..be58127d06 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-137-fibonacci-golden-nuggets.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-137-fibonacci-golden-nuggets.md
@@ -14,7 +14,8 @@ dashedName: problem-137-fibonacci-golden-nuggets
 
 Дивовижно,
 
-$$\begin{align} A_F(\frac{1}{2}) & = (\frac{1}{2}) × 1 + {(\frac{1}{2})}^2 × 1 + {(\frac{1}{2})}^3 × 2 + {(\frac{1}{2})}^4 × 3 + {(\frac{1}{2})}^5 × 5 + \cdots \\\\ & = \frac{1}{2} + \frac{1}{4} + \frac{2}{8} + \frac{3}{16} + \frac{5}{32} + \cdots \\\\ & = 2 \end{align}$$
+$$\begin{align} A_F(\frac{1}{2}) & = (\frac{1}{2}) × 1 + {(\frac{1}{2})}^2 × 1 + {(\frac{1}{2})}^3 × 2 + {(\frac{1}{2})}^4 × 3 + {(\frac{1}{2})}^5 × 5 + \cdots \\\\
+                 & = \frac{1}{2} + \frac{1}{4} + \frac{2}{8} + \frac{3}{16} + \frac{5}{32} + \cdots \\\\ & = 2 \end{align}$$
 
 Відповідні значення $x$ для перших п'яти натуральних чисел наведено нижче.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-150-searching-a-triangular-array-for-a-sub-triangle-having-minimum-sum.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-150-searching-a-triangular-array-for-a-sub-triangle-having-minimum-sum.md
index deb5c77473..c6969e6146 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-150-searching-a-triangular-array-for-a-sub-triangle-having-minimum-sum.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-150-searching-a-triangular-array-for-a-sub-triangle-having-minimum-sum.md
@@ -17,13 +17,17 @@ dashedName: problem-150-searching-a-triangular-array-for-a-sub-triangle-having-m
 
 Ми хочемо створити такий трикутний масив з тисячею рядків, тому ми генеруємо 500500 псевдовипадкових чисел $s_k$ у діапазоні $±2^{19}$, використовуючи тип генератора випадкових чисел (відомий як лінійний конгруентний метод) наступним чином:
 
-$$\begin{align} t := & \\ 0\\\\ \text{for}\\ & k = 1\\ \text{up to}\\ k = 500500:\\\\ & t := (615949 × t + 797807)\\ \text{modulo}\\ 2^{20}\\\\ & s_k := t − 219\\\\ \end{align}$$
+$$\begin{align}   t := & \\ 0\\\\
+  \text{for}\\ & k = 1\\ \text{up to}\\ k = 500500:\\\\   & t := (615949 × t + 797807)\\ \text{modulo}\\ 2^{20}\\\\
+  & s_k := t − 219\\\\ \end{align}$$
 
 Таким чином: $s_1 = 273519$, $s_2 = −153582$, $s_3 = 450905$ і т. д.
 
 Трикутний масив утворений з використанням псевдовипадкових чисел:
 
-$$ s_1 \\\\ s_2\\;s_3 \\\\ s_4\\; s_5\\; s_6 \\\\ s_7\\; s_8\\; s_9\\; s_{10} \\\\ \ldots $$
+$$ s_1 \\\\
+s_2\\;s_3 \\\\ s_4\\; s_5\\; s_6 \\\\
+s_7\\; s_8\\; s_9\\; s_{10} \\\\ \ldots $$
 
 Менші трикутники можуть починатися з будь-якого елемента масиву і сягати вниз як завгодно далеко (захоплюючи два елементи безпосередньо під ним з наступного ряду, три елементи безпосередньо під ним з наступного ряду і так далі).
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-157-solving-the-diophantine-equation.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-157-solving-the-diophantine-equation.md
index e3785449ce..5ed86a8483 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-157-solving-the-diophantine-equation.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-157-solving-the-diophantine-equation.md
@@ -12,7 +12,10 @@ dashedName: problem-157-solving-the-diophantine-equation
 
 Якщо $n = 1$ дане рівняння має 20 розв'язків, показаних нижче:
 
-$$\begin{array}{lllll} \frac{1}{1}  + \frac{1}{1}  = \frac{20}{10} & \frac{1}{1} + \frac{1}{2}  = \frac{15}{10} & \frac{1}{1}  + \frac{1}{5}  = \frac{12}{10} & \frac{1}{1} + \frac{1}{10} = \frac{11}{10} & \frac{1}{2}  + \frac{1}{2}  = \frac{10}{10} \\\\ \frac{1}{2}  + \frac{1}{5}  = \frac{7}{10}   & \frac{1}{2} + \frac{1}{10} = \frac{6}{10} & \frac{1}{3}  + \frac{1}{6}  = \frac{5}{10}   & \frac{1}{3} + \frac{1}{15} = \frac{4}{10} & \frac{1}{4}  + \frac{1}{4}  = \frac{5}{10} \\\\ \frac{1}{4}  + \frac{1}{4}  = \frac{5}{10}  & \frac{1}{5}  + \frac{1}{5}  = \frac{4}{10} & \frac{1}{5}  + \frac{1}{10} = \frac{3}{10}  & \frac{1}{6}  + \frac{1}{30} = \frac{2}{10} & \frac{1}{10} + \frac{1}{10} = \frac{2}{10} \\\\ \frac{1}{11} + \frac{1}{110} = \frac{1}{10} & \frac{1}{12} + \frac{1}{60}  = \frac{1}{10} & \frac{1}{14} + \frac{1}{35}  = \frac{1}{10} & \frac{1}{15} + \frac{1}{30}  = \frac{1}{10} & \frac{1}{20} + \frac{1}{20}  = \frac{1}{10} \end{array}$$
+$$\begin{array}{lllll} \frac{1}{1}  + \frac{1}{1}  = \frac{20}{10} & \frac{1}{1} + \frac{1}{2}  = \frac{15}{10} & \frac{1}{1}  + \frac{1}{5}  = \frac{12}{10} & \frac{1}{1} + \frac{1}{10} = \frac{11}{10} & \frac{1}{2}  + \frac{1}{2}  = \frac{10}{10} \\\\
+  \frac{1}{2}  + \frac{1}{5}  = \frac{7}{10}   & \frac{1}{2} + \frac{1}{10} = \frac{6}{10} & \frac{1}{3}  + \frac{1}{6}  = \frac{5}{10}   & \frac{1}{3} + \frac{1}{15} = \frac{4}{10} & \frac{1}{4}  + \frac{1}{4}  = \frac{5}{10} \\\\
+  \frac{1}{4}  + \frac{1}{4}  = \frac{5}{10}  & \frac{1}{5}  + \frac{1}{5}  = \frac{4}{10} & \frac{1}{5}  + \frac{1}{10} = \frac{3}{10}  & \frac{1}{6}  + \frac{1}{30} = \frac{2}{10} & \frac{1}{10} + \frac{1}{10} = \frac{2}{10} \\\\
+  \frac{1}{11} + \frac{1}{110} = \frac{1}{10} & \frac{1}{12} + \frac{1}{60}  = \frac{1}{10} & \frac{1}{14} + \frac{1}{35}  = \frac{1}{10} & \frac{1}{15} + \frac{1}{30}  = \frac{1}{10} & \frac{1}{20} + \frac{1}{20}  = \frac{1}{10} \end{array}$$
 
 Скільки розв'язків має це рівняння, якщо $1 ≤ n 9$?
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-159-digital-root-sums-of-factorisations.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-159-digital-root-sums-of-factorisations.md
index 32290612e1..b6be367c99 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-159-digital-root-sums-of-factorisations.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-159-digital-root-sums-of-factorisations.md
@@ -12,7 +12,10 @@ dashedName: problem-159-digital-root-sums-of-factorisations
 
 Наприклад, за виключенням множення на один, 24 можна факторизувати 7 різними способами:
 
-$$\begin{align} & 24 = 2 \times 2 \times 2 \times 3\\\\ & 24 = 2 \times 3 \times 4  \\\\ & 24 = 2 \times 2 \times 6  \\\\ & 24 = 4 \times 6    \\\\ & 24 = 3 \times 8    \\\\ & 24 = 2 \times 12   \\\\ & 24 = 24 \end{align}$$
+$$\begin{align}   & 24 = 2 \times 2 \times 2 \times 3\\\\
+  & 24 = 2 \times 3 \times 4  \\\\   & 24 = 2 \times 2 \times 6  \\\\
+  & 24 = 4 \times 6    \\\\   & 24 = 3 \times 8    \\\\
+  & 24 = 2 \times 12   \\\\ & 24 = 24 \end{align}$$
 
 Нагадаємо, що цифровий корінь числа в основі 10 знаходять додаванням цифр цього числа, повторюючи процес, поки число не буде менше ніж 10. Цифровий корінь 467 буде 8.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-160-factorial-trailing-digits.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-160-factorial-trailing-digits.md
index dfa292654f..0d864c00be 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-160-factorial-trailing-digits.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-160-factorial-trailing-digits.md
@@ -12,7 +12,8 @@ dashedName: problem-160-factorial-trailing-digits
 
 Наприклад,
 
-$$\begin{align} & 9! = 362880 \\; \text{so} \\; f(9) = 36288 \\\\ & 10! = 3628800 \\; \text{so} \\; f(10) = 36288 \\\\ & 20! = 2432902008176640000 \\; \text{so} \\; f(20) = 17664 \end{align}$$
+$$\begin{align}   & 9! = 362880 \\; \text{so} \\; f(9) = 36288 \\\\
+  & 10! = 3628800 \\; \text{so} \\; f(10) = 36288 \\\\ & 20! = 2432902008176640000 \\; \text{so} \\; f(20) = 17664 \end{align}$$
 
 Знайдіть $f(1,000,000,000,000)$
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-163-cross-hatched-triangles.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-163-cross-hatched-triangles.md
index 068def72dd..81f5c18d6d 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-163-cross-hatched-triangles.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-163-cross-hatched-triangles.md
@@ -18,7 +18,8 @@ dashedName: problem-163-cross-hatched-triangles
 
 Якщо позначити $T(n)$ як кількість трикутників, що містяться в трикутнику розміру $n$, тоді
 
-$$\begin{align} & T(1) = 16 \\\\ & T(2) = 104 \end{align}$$
+$$\begin{align}   & T(1) = 16 \\\\
+  & T(2) = 104 \end{align}$$
 
 Знайдіть $T(36)$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-165-intersections.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-165-intersections.md
index e850e08059..8609599b38 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-165-intersections.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-165-intersections.md
@@ -16,13 +16,17 @@ dashedName: problem-165-intersections
 
 Розглянемо три сегменти $L_1$, $L_2$та $L_3$:
 
-$\begin{align} & L_1: (27, 44) \\;\text{to}\\; (12, 32) \\\\ & L_2: (46, 53) \\;\tтекст{to}\\; (17, 62) \\\\ & L_3: (46, 70) \\;\tтекст{to}\\; (22, 40) \\\\ \end{align}$$
+$\begin{align}   & L_1: (27, 44) \\;\text{to}\\; (12, 32) \\\\
+  & L_2: (46, 53) \\;\tтекст{to}\\; (17, 62) \\\\   & L_3: (46, 70) \\;\tтекст{to}\\; (22, 40) \\\\
+\end{align}$$
 
 Можна перевірити, що відрізки ліній $L_2$ і $L_3$ мають справжню точку перетину. Ми зазначали, що, якщо одна з кінцевих точок $L_3$: (22, 40) лежить на $L_1$, це не вважається справжньою точкою перетину. $L_1$ і $L_2$ не мають спільної точки. Отже, на трьох відрізках прямої ми знаходимо одну справжню точку перетину.
 
 Тепер зробімо те саме для 5000 прямих відрізків. З цією метою ми згенеруємо 20000 чисел, використовуючи так званий генератор псевдо-випадкових чисел «Blum Blum Shub».
 
-$\begin{align} & s_0 = 290797 \\\\ & s_{n + 1} = s_n × s_n (\text{modulo}\\; 50515093) \\\\ & t_n = s_n (\text{modulo}\\; 500) \\\\ \end{align}$
+$\begin{align}   & s_0 = 290797 \\\\
+  & s_{n + 1} = s_n × s_n (\text{modulo}\\; 50515093) \\\\   & t_n = s_n (\text{modulo}\\; 500) \\\\
+\end{align}$
 
 Щоб створити кожен відрізок, ми використовуємо чотири послідовних числа $t_n$. Тобто перший відрізок дано:
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-166-criss-cross.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-166-criss-cross.md
index 0824421772..24939ffbab 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-166-criss-cross.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-166-criss-cross.md
@@ -12,7 +12,9 @@ dashedName: problem-166-criss-cross
 
 Видно, що в таблиці
 
-$$\begin{array}{} 6 & 3 & 3 & 0 \\\\ 5 & 0 & 4 & 3 \\\\ 0 & 7 & 1 & 4 \\\\ 1 & 2 & 4 & 5 \end{array}$$
+$$\begin{array}{}   6 & 3 & 3 & 0 \\\\
+  5 & 0 & 4 & 3 \\\\   0 & 7 & 1 & 4 \\\\
+  1 & 2 & 4 & 5 \end{array}$$
 
 сума кожного рядка та кожного стовпця має значення 12. Крім того, сума кожної діагоналі також дорівнює 12.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-169-exploring-the-number-of-different-ways-a-number-can-be-expressed-as-a-sum-of-powers-of-2.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-169-exploring-the-number-of-different-ways-a-number-can-be-expressed-as-a-sum-of-powers-of-2.md
index 0a4ebe5dce..38f200b593 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-169-exploring-the-number-of-different-ways-a-number-can-be-expressed-as-a-sum-of-powers-of-2.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-169-exploring-the-number-of-different-ways-a-number-can-be-expressed-as-a-sum-of-powers-of-2.md
@@ -14,7 +14,9 @@ dashedName: >-
 
 Наприклад: $f(10)=5$, оскільки існує 5 різних способів виразити 10:
 
-$$\begin{align} & 1 + 1 + 8 \\\\ & 1 + 1 + 4 + 4 \\\\ & 1 + 1 + 2 + 2 + 4 \\\\ & 2 + 4 + 4 \\\\ & 2 + 8 \end{align}$$
+$$\begin{align}   & 1 + 1 + 8 \\\\
+  & 1 + 1 + 4 + 4 \\\\   & 1 + 1 + 2 + 2 + 4 \\\\
+  & 2 + 4 + 4 \\\\ & 2 + 8 \end{align}$$
 
 Що таке $f({10}^{25})$?
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-170-find-the-largest-0-to-9-pandigital-that-can-be-formed-by-concatenating-products.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-170-find-the-largest-0-to-9-pandigital-that-can-be-formed-by-concatenating-products.md
index 53b04565d7..840e5eb392 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-170-find-the-largest-0-to-9-pandigital-that-can-be-formed-by-concatenating-products.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-170-find-the-largest-0-to-9-pandigital-that-can-be-formed-by-concatenating-products.md
@@ -12,7 +12,8 @@ dashedName: >-
 
 Помножте число 6 на кожне з 1273 і 9854:
 
-$$\begin{align} & 6 × 1273 = 7638 \\\\ & 6 × 9854 = 59124 \\\\ \end{align}$$
+$$\begin{align}   & 6 × 1273 = 7638 \\\\
+  & 6 × 9854 = 59124 \\\\ \end{align}$$
 
 Об’єднавши ці добутки, отримуємо панцифрове число від 1 до 9 - 763859124. Нехай 763859124 — об'єднаний добуток 6 і (1273, 9854)". Зауважте також, що об'єднання вхідних чисел 612739854 також становить панцифрове число від 1 до 9.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-171-finding-numbers-for-which-the-sum-of-the-squares-of-the-digits-is-a-square.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-171-finding-numbers-for-which-the-sum-of-the-squares-of-the-digits-is-a-square.md
index 95b9e6f403..91de357fc8 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-171-finding-numbers-for-which-the-sum-of-the-squares-of-the-digits-is-a-square.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-171-finding-numbers-for-which-the-sum-of-the-squares-of-the-digits-is-a-square.md
@@ -12,7 +12,9 @@ dashedName: >-
 
 Для додатного цілого числа $n$, нехай $f(n)$ — це сума квадратів чисел (з основою 10) $n$, наприклад.
 
-$$\begin{align} & f(3) = 3^2 = 9 \\\\ & f(25) = 2^2 + 5^2 = 4 + 25 = 29 \\\\ & f(442) = 4^2 + 4^2 + 2^2 = 16 + 16 + 4 = 36 \\\\ \end{align}$$
+$$\begin{align}   & f(3) = 3^2 = 9 \\\\
+  & f(25) = 2^2 + 5^2 = 4 + 25 = 29 \\\\   & f(442) = 4^2 + 4^2 + 2^2 = 16 + 16 + 4 = 36 \\\\
+\end{align}$$
 
 Знайдіть останні дев'ять чисел суми усіх $n$, $0 &lt; n &lt; {10}^{20}$, якщо $f(n)$ є повним квадратом.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-180-rational-zeros-of-a-function-of-three-variables.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-180-rational-zeros-of-a-function-of-three-variables.md
index 1d32b9934f..321f6221a8 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-180-rational-zeros-of-a-function-of-three-variables.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-180-rational-zeros-of-a-function-of-three-variables.md
@@ -10,7 +10,8 @@ dashedName: problem-180-rational-zeros-of-a-function-of-three-variables
 
 Для будь-якого цілого числа $n$ розглянемо три функції
 
-$$\begin{align} & f_{1,n}(x,y,z) = x^{n + 1} + y^{n + 1} − z^{n + 1}\\\\ & f_{2,n}(x,y,z) = (xy + yz + zx) \times (x^{n - 1} + y^{n - 1} − z^{n - 1})\\\\ & f_{3,n}(x,y,z) = xyz \times (x^{n - 2} + y^{n - 2} − z^{n - 2}) \end{align}$$
+$$\begin{align}   & f_{1,n}(x,y,z) = x^{n + 1} + y^{n + 1} − z^{n + 1}\\\\
+  & f_{2,n}(x,y,z) = (xy + yz + zx) \times (x^{n - 1} + y^{n - 1} − z^{n - 1})\\\\ & f_{3,n}(x,y,z) = xyz \times (x^{n - 2} + y^{n - 2} − z^{n - 2}) \end{align}$$
 
 та їхню комбінацію
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-185-number-mind.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-185-number-mind.md
index 512aec56f4..bc3c36d6d2 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-185-number-mind.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-185-number-mind.md
@@ -14,7 +14,10 @@ dashedName: problem-185-number-mind
 
 Наприклад, для секретної послідовності 5 цифр,
 
-$$\begin{align} & 90342 ;2\\;\text{correct}\\\\ & 70794 ;0\\;\text{correct}\\\\ & 39458 ;2\\;\text{correct}\\\\ & 34109 ;1\\;\text{correct}\\\\ & 51545 ;2\\;\text{correct}\\\\ & 12531 ;1\\;\text{correct} \end{align}$$
+$$\begin{align}   & 90342 ;2\\;\text{correct}\\\\
+  & 70794 ;0\\;\text{correct}\\\\   & 39458 ;2\\;\text{correct}\\\\
+  & 34109 ;1\\;\text{correct}\\\\   & 51545 ;2\\;\text{correct}\\\\
+  & 12531 ;1\\;\text{correct} \end{align}$$
 
 Правильна послідовність 39542 унікальна.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-196-prime-triplets.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-196-prime-triplets.md
index 7cd216b932..bac49252c8 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-196-prime-triplets.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-196-prime-triplets.md
@@ -10,7 +10,13 @@ dashedName: problem-196-prime-triplets
 
 Побудуйте трикутник з усіх додатних чисел наступним чином:
 
-$$\begin{array}{rrr} &  1 \\\\ &  \color{red}{2} &  \color{red}{3} \\\\ &  4 & \color{red}{5} &  6 \\\\ &  \color{red}{7} &  8 &  9 & 10 \\\\ & \color{red}{11} & 12 & \color{red}{13} & 14 & 15  \\\\ & 16 & \color{red}{17} & 18 & \color{red}{19} & 20 & 21 \\\\ & 22 & \color{red}{23} & 24 & 25 & 26 & 27 & 28 \\\\ & \color{red}{29} & 30 & \color{red}{31} & 32 & 33 & 34 & 35 & 36 \\\\ & \color{red}{37} & 38 & 39 & 40 & \color{red}{41} & 42 & \color{red}{43} & 44 & 45 \\\\ & 46 & \color{red}{47} & 48 & 49 & 50 & 51 & 52 & \color{red}{53} & 54 & 55 \\\\ & 56 & 57 & 58 & \color{red}{59} & 60 & \color{red}{61} & 62 & 63 & 64 & 65 & 66 \\\\ & \cdots \end{array}$$
+$$\begin{array}{rrr}   &  1 \\\\
+  &  \color{red}{2} &  \color{red}{3} \\\\   &  4 & \color{red}{5} &  6 \\\\
+  &  \color{red}{7} &  8 &  9 & 10 \\\\   & \color{red}{11} & 12 & \color{red}{13} & 14 & 15  \\\\
+  & 16 & \color{red}{17} & 18 & \color{red}{19} & 20 & 21 \\\\   & 22 & \color{red}{23} & 24 & 25 & 26 & 27 & 28 \\\\
+  & \color{red}{29} & 30 & \color{red}{31} & 32 & 33 & 34 & 35 & 36 \\\\   & \color{red}{37} & 38 & 39 & 40 & \color{red}{41} & 42 & \color{red}{43} & 44 & 45 \\\\
+  & 46 & \color{red}{47} & 48 & 49 & 50 & 51 & 52 & \color{red}{53} & 54 & 55 \\\\   & 56 & 57 & 58 & \color{red}{59} & 60 & \color{red}{61} & 62 & 63 & 64 & 65 & 66 \\\\
+  & \cdots \end{array}$$
 
 У трикутнику біля кожного додатного числа є ще до восьми чисел.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-201-subsets-with-a-unique-sum.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-201-subsets-with-a-unique-sum.md
index bcd4d4105b..8659bc9dbe 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-201-subsets-with-a-unique-sum.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-201-subsets-with-a-unique-sum.md
@@ -12,7 +12,17 @@ dashedName: problem-201-subsets-with-a-unique-sum
 
 Розглянемо набір $B = \\{1,3,6,8,10,11\\}$. Існує 20 підмножин $B$, що містять три елементи, і їх сумидорівнюють:
 
-$$\begin{align} & sum(\\{1,3,6\\}) = 10 \\\\ & sum(\\{1,3,8\\}) = 12 \\\\ & sum(\\{1,3,10\\}) = 14 \\\\ & sum(\\{1,3,11\\}) = 15 \\\\ & sum(\\{1,6,8\\}) = 15 \\\\ & sum(\\{1,6,10\\}) = 17 \\\\ & sum(\\{1,6,11\\}) = 18 \\\\ & sum(\\{1,8,10\\}) = 19 \\\\ & sum(\\{1,8,11\\}) = 20 \\\\ & sum(\\{1,10,11\\}) = 22 \\\\ & sum(\\{3,6,8\\}) = 17 \\\\ & sum(\\{3,6,10\\}) = 19 \\\\ & sum(\\{3,6,11\\}) = 20 \\\\ & sum(\\{3,8,10\\}) = 21 \\\\ & sum(\\{3,8,11\\}) = 22 \\\\ & sum(\\{3,10,11\\}) = 24 \\\\ & sum(\\{6,8,10\\}) = 24 \\\\ & sum(\\{6,8,11\\}) = 25 \\\\ & sum(\\{6,10,11\\}) = 27 \\\\ & sum(\\{8,10,11\\}) = 29 \\end{align}$$
+$$\begin{align}   & sum(\\{1,3,6\\}) = 10 \\\\
+  & sum(\\{1,3,8\\}) = 12 \\\\   & sum(\\{1,3,10\\}) = 14 \\\\
+  & sum(\\{1,3,11\\}) = 15 \\\\   & sum(\\{1,6,8\\}) = 15 \\\\
+  & sum(\\{1,6,10\\}) = 17 \\\\   & sum(\\{1,6,11\\}) = 18 \\\\
+  & sum(\\{1,8,10\\}) = 19 \\\\   & sum(\\{1,8,11\\}) = 20 \\\\
+  & sum(\\{1,10,11\\}) = 22 \\\\   & sum(\\{3,6,8\\}) = 17 \\\\
+  & sum(\\{3,6,10\\}) = 19 \\\\   & sum(\\{3,6,11\\}) = 20 \\\\
+  & sum(\\{3,8,10\\}) = 21 \\\\   & sum(\\{3,8,11\\}) = 22 \\\\
+  & sum(\\{3,10,11\\}) = 24 \\\\   & sum(\\{6,8,10\\}) = 24 \\\\
+  & sum(\\{6,8,11\\}) = 25 \\\\   & sum(\\{6,10,11\\}) = 27 \\\\
+  & sum(\\{8,10,11\\}) = 29 \\end{align}$$
 
 Деякі з цих сум трапляються більше, ніж один раз, інші - унікальні. Для набору $A$ нехай $U(A,k)$ буде набором унікальних сум $k$-елементних підмножин $A$, у нашому прикладі ми знаходимо $U(B,3) = \\{10,12,14,18,21,25,27,29\\}$ і $sum(U(B,3)) = 156$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-203-squarefree-binomial-coefficients.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-203-squarefree-binomial-coefficients.md
index 3b167d21f6..3c67159937 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-203-squarefree-binomial-coefficients.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-203-squarefree-binomial-coefficients.md
@@ -10,7 +10,11 @@ dashedName: problem-203-squarefree-binomial-coefficients
 
 Біноміальні коефіцієнти $\displaystyle\binom{n}{k}$ можна розташувати у формі трикутника (трикутник Паскаля) наступним чином:
 
-$$\begin{array}{ccccccccccccccc} &   &   &   &    &    &    &  1 &    &    &    &   &   &   &   \\\\ &   &   &   &    &    &  1 &    & 1  &    &    &   &   &   &   \\\\ &   &   &   &    &  1 &    &  2 &    &  1 &    &   &   &   &   \\\\ &   &   &   &  1 &    &  3 &    &  3 &    &  1 &   &   &   &   \\\\ &   &   & 1 &    &  4 &    &  6 &    &  4 &    & 1 &   &   &   \\\\ &   & 1 &   &  5 &    & 10 &    & 10 &    &  5 &   & 1 &   &   \\\\ & 1 &   & 6 &    & 15 &    & 20 &    & 15 &    & 6 &   & 1 &   \\\\ 1 &   & 7 &   & 21 &    & 35 &    & 35 &    & 21 &   & 7 &   & 1 \\\\ &   &   &   &    &    &    & \ldots \end{array}$$
+$$\begin{array}{ccccccccccccccc}    &   &   &   &    &    &    &  1 &    &    &    &   &   &   &   \\\\
+   &   &   &   &    &    &  1 &    & 1  &    &    &   &   &   &   \\\\    &   &   &   &    &  1 &    &  2 &    &  1 &    &   &   &   &   \\\\
+   &   &   &   &  1 &    &  3 &    &  3 &    &  1 &   &   &   &   \\\\    &   &   & 1 &    &  4 &    &  6 &    &  4 &    & 1 &   &   &   \\\\
+   &   & 1 &   &  5 &    & 10 &    & 10 &    &  5 &   & 1 &   &   \\\\    & 1 &   & 6 &    & 15 &    & 20 &    & 15 &    & 6 &   & 1 &   \\\\
+ 1 &   & 7 &   & 21 &    & 35 &    & 35 &    & 21 &   & 7 &   & 1 \\\\ &   &   &   &    &    &    & \ldots \end{array}$$
 
 Можна побачити, що перші вісім рядків трикутника Паскаля містять дванадцять різних чисел: 1, 2, 3, 4, 5, 6, 7, 10, 15, 20, 21 та 35.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-207-integer-partition-equations.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-207-integer-partition-equations.md
index 44e31a2704..e2ad59ae5c 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-207-integer-partition-equations.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-207-integer-partition-equations.md
@@ -20,7 +20,11 @@ dashedName: problem-207-integer-partition-equations
 
 У таблиці нижче перераховано деякі значення $P(m)$
 
-$$\begin{align} & P(5) = \frac{1}{1}    \\\\ & P(10) = \frac{1}{2}   \\\\ & P(15) = \frac{2}{3}   \\\\ & P(20) = \frac{1}{2}   \\\\ & P(25) = \frac{1}{2}   \\\\ & P(30) = \frac{2}{5}   \\\\ & \ldots                \\\\ & P(180) = \frac{1}{4}  \\\\ & P(185) = \frac{3}{13} \end{align}$$
+$$\begin{align}   & P(5) = \frac{1}{1}    \\\\
+  & P(10) = \frac{1}{2}   \\\\   & P(15) = \frac{2}{3}   \\\\
+  & P(20) = \frac{1}{2}   \\\\   & P(25) = \frac{1}{2}   \\\\
+  & P(30) = \frac{2}{5}   \\\\   & \ldots                \\\\
+  & P(180) = \frac{1}{4}  \\\\ & P(185) = \frac{3}{13} \end{align}$$
 
 Знайдіть найменший $m$ для якого $P(m) &lt; \frac{1}{12\\,345}$
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-212-combined-volume-of-cuboids.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-212-combined-volume-of-cuboids.md
index 33519e4c23..3f3785efb5 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-212-combined-volume-of-cuboids.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-212-combined-volume-of-cuboids.md
@@ -12,7 +12,10 @@ dashedName: problem-212-combined-volume-of-cuboids
 
 Нехай $C_1, \ldots, C_{50000}$ — це набір 50000 вирівняних по осі паралелепіпедів, кожен паралелепіпед $C_n$ має такі параметри
 
-$$\begin{align} & x_0 = S_{6n - 5} \\; \text{modulo} \\; 10000    \\\\ & y_0 = S_{6n - 4} \\; \text{modulo} \\; 10000    \\\\ & z_0 = S_{6n - 3} \\; \text{modulo} \\; 10000    \\\\ & dx = 1 + (S_{6n - 2} \\; \text{modulo} \\; 399) \\\\ & dy = 1 + (S_{6n - 1} \\; \text{modulo} \\; 399) \\\\ & dz = 1 + (S_{6n} \\; \text{modulo} \\; 399)     \\\\ \end{align}$$
+$$\begin{align}   & x_0 = S_{6n - 5} \\; \text{modulo} \\; 10000    \\\\
+  & y_0 = S_{6n - 4} \\; \text{modulo} \\; 10000    \\\\   & z_0 = S_{6n - 3} \\; \text{modulo} \\; 10000    \\\\
+  & dx = 1 + (S_{6n - 2} \\; \text{modulo} \\; 399) \\\\   & dy = 1 + (S_{6n - 1} \\; \text{modulo} \\; 399) \\\\
+  & dz = 1 + (S_{6n} \\; \text{modulo} \\; 399)     \\\\ \end{align}$$
 
 де $S_1, \ldots, S_{300000}$ отримуємо через генератор Фібоначчі:
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-214-totient-chains.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-214-totient-chains.md
index 75a4d04c9a..a4b7349c2e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-214-totient-chains.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-214-totient-chains.md
@@ -12,7 +12,11 @@ dashedName: problem-214-totient-chains
 
 При повторенні функції $φ$, кожне додатне ціле число утворює спадну послідовність чисел, що закінчується одиницею. Наприклад, якщо ми почнемо з 5, то утвориться послідовність 5,4,2,1. Ось список послідовностей, що складаються з 4 цифр:
 
-$$\begin{align} 5,4,2,1 & \\\\ 7,6,2,1 & \\\\ 8,4,2,1 & \\\\ 9,6,2,1 & \\\\ 10,4,2,1 & \\\\ 12,4,2,1 & \\\\ 14,6,2,1 & \\\\ 18,6,2,1 & \end{align}$$
+$$\begin{align}    5,4,2,1 & \\\\
+   7,6,2,1 & \\\\    8,4,2,1 & \\\\
+   9,6,2,1 & \\\\   10,4,2,1 & \\\\
+  12,4,2,1 & \\\\   14,6,2,1 & \\\\
+  18,6,2,1 & \end{align}$$
 
 Лише дві з цих послідовностей починаються з простого числа, їхня сума — 12.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-228-minkowski-sums.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-228-minkowski-sums.md
index 6aa28bba79..fad671e163 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-228-minkowski-sums.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-228-minkowski-sums.md
@@ -10,7 +10,8 @@ dashedName: problem-228-minkowski-sums
 
 Нехай $S_n$ — це правильний $n$-сторонній багатокутник або фігура, у якої вершини $v_k (k = 1, 2, \ldots, n)$ мають координати:
 
-$$\begin{align} & x_k = cos(\frac{2k - 1}{n} × 180°) \\\\ & y_k = sin(\frac{2k - 1}{n} × 180°) \end{align}$$
+$$\begin{align} & x_k = cos(\frac{2k - 1}{n} × 180°) \\\\
+& y_k = sin(\frac{2k - 1}{n} × 180°) \end{align}$$
 
 Кожен $S_n$ зображено зафарбованою фігурою, яка складається з усіх точок на периметрі та всередині.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-229-four-representations-using-squares.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-229-four-representations-using-squares.md
index 0b69dd3144..83e90a2fd0 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-229-four-representations-using-squares.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-229-four-representations-using-squares.md
@@ -10,13 +10,17 @@ dashedName: problem-229-four-representations-using-squares
 
 Розглянемо число 3600. Воно дуже особливе, оскільки
 
-$$\begin{align} & 3600 = {48}^2 + {36}^2   \\\\ & 3600 = {20}^2 + {2×40}^2 \\\\ & 3600 = {30}^2 + {3×30}^2 \\\\ & 3600 = {45}^2 + {7×15}^2 \\\\ \end{align}$$
+$$\begin{align}   & 3600 = {48}^2 + {36}^2   \\\\
+  & 3600 = {20}^2 + {2×40}^2 \\\\   & 3600 = {30}^2 + {3×30}^2 \\\\
+  & 3600 = {45}^2 + {7×15}^2 \\\\ \end{align}$$
 
 Аналогічно бачимо, що $88201 = {99}^2 + {280}^2 = {287}^2 + 2 × {54}^2 = {283}^2 + 3 × {52}^2 = {197}^2 + 7 × {84}^2$.
 
 У 1747 році Ейлер довів які числа є сумою двох квадратів. Нас цікавлять числа $n$, які можна виразити через наступні чотири формули:
 
-$$\begin{align} & n = {a_1}^2 + {b_1}^2  \\\\ & n = {a_2}^2 + 2{b_2}^2 \\\\ & n = {a_3}^2 + 3{b_3}^2 \\\\ & n = {a_7}^2 + 7{b_7}^2 \\\\ \end{align}$$
+$$\begin{align}   & n = {a_1}^2 + {b_1}^2  \\\\
+  & n = {a_2}^2 + 2{b_2}^2 \\\\   & n = {a_3}^2 + 3{b_3}^2 \\\\
+  & n = {a_7}^2 + 7{b_7}^2 \\\\ \end{align}$$
 
 де $a_k$ та $b_k$ додатні цілі числа.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-230-fibonacci-words.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-230-fibonacci-words.md
index 1d98fa030f..c782045494 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-230-fibonacci-words.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-230-fibonacci-words.md
@@ -18,17 +18,21 @@ dashedName: problem-230-fibonacci-words
 
 Першими елементами $F_{A,B}$ є:
 
-$$\begin{align} & 1\\,415\\,926\\,535 \\\\ & 8\\,979\\,323\\,846 \\\\ & 14\\,159\\,265\\,358\\,979\\,323\\,846 \\\\ & 897\\,932\\,384\\,614\\,159\\,265\\,358\\,979\\,323\\,846 \\\\ & 14\\,159\\,265\\,358\\,979\\,323\\,846\\,897\\,932\\,384\\,614\\,15\color{red}{9}\\,265\\,358\\,979\\,323\\,846 \end{align}$$
+$$\begin{align}   & 1\\,415\\,926\\,535 \\\\
+  & 8\\,979\\,323\\,846 \\\\   & 14\\,159\\,265\\,358\\,979\\,323\\,846 \\\\
+  & 897\\,932\\,384\\,614\\,159\\,265\\,358\\,979\\,323\\,846 \\\\ & 14\\,159\\,265\\,358\\,979\\,323\\,846\\,897\\,932\\,384\\,614\\,15\color{red}{9}\\,265\\,358\\,979\\,323\\,846 \end{align}$$
 
 Тоді $D_{A,B}(35)$ — це ${35}^{\text{th}}$ цифра п'ятого елемента, тобто 9.
 
 Тепер для $A$ використовуємо перші 100 цифр після десяткового розділювача:
 
-$$\begin{align} & 14\\,159\\,265\\,358\\,979\\,323\\,846\\,264\\,338\\,327\\,950\\,288\\,419\\,716\\,939\\,937\\,510 \\\\ & 58\\,209\\,749\\,445\\,923\\,078\\,164\\,062\\,862\\,089\\,986\\,280\\,348\\,253\\,421\\,170\\,679 \end{align}$$
+$$\begin{align}   & 14\\,159\\,265\\,358\\,979\\,323\\,846\\,264\\,338\\,327\\,950\\,288\\,419\\,716\\,939\\,937\\,510 \\\\
+  & 58\\,209\\,749\\,445\\,923\\,078\\,164\\,062\\,862\\,089\\,986\\,280\\,348\\,253\\,421\\,170\\,679 \end{align}$$
 
 і для $B$ наступні 100 цифр:
 
-$$\begin{align} & 82\\,148\\,086\\,513\\,282\\,306\\,647\\,093\\,844\\,609\\,550\\,582\\,231\\,725\\,359\\,408\\,128 \\\\ & 48\\,111\\,745\\,028\\,410\\,270\\,193\\,852\\,110\\,555\\,964\\,462\\,294\\,895\\,493\\,038\\,196 \end{align}$$
+$$\begin{align}   & 82\\,148\\,086\\,513\\,282\\,306\\,647\\,093\\,844\\,609\\,550\\,582\\,231\\,725\\,359\\,408\\,128 \\\\
+  & 48\\,111\\,745\\,028\\,410\\,270\\,193\\,852\\,110\\,555\\,964\\,462\\,294\\,895\\,493\\,038\\,196 \end{align}$$
 
 Знайдіть $\sum_{n = 0, 1, \ldots, 17} {10}^n × D_{A,B}((127 + 19n) × 7^n)$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-238-infinite-string-tour.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-238-infinite-string-tour.md
index 646241dd28..ec5c4154ad 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-238-infinite-string-tour.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-238-infinite-string-tour.md
@@ -10,7 +10,8 @@ dashedName: problem-238-infinite-string-tour
 
 Створіть послідовність чисел, використовуючи генератор псевдовипадкових чисел "Блум Блум Шуба":
 
-$$ s_0 = 14025256 \\\\ s_{n + 1} = {s_n}^2 \\; mod \\; 20\\,300\\,713 $$
+$$ s_0 = 14025256 \\\\
+s_{n + 1} = {s_n}^2 \\; mod \\; 20\\,300\\,713 $$
 
 Об'єднайте ці числа $s_0s_1s_2\ldots$, щоб створити рядок $w$ нескінченної довжини. Тоді $w = 14025256741014958470038053646\ldots$
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-240-top-dice.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-240-top-dice.md
index 61956fc685..46483ccf4f 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-240-top-dice.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-240-top-dice.md
@@ -10,7 +10,9 @@ dashedName: problem-240-top-dice
 
 Якщо кинути п'ять 6-гранних кубиків (грані пронумеровано від 1 до 6), у 1111 випадках сума трьох найбільших чисел дорівнюватиме 15. Ось декілька прикладів:
 
-$$\begin{align} & D_1,D_2,D_3,D_4,D_5 = 4,3,6,3,5 \\\\ & D_1,D_2,D_3,D_4,D_5 = 4,3,3,5,6 \\\\ & D_1,D_2,D_3,D_4,D_5 = 3,3,3,6,6 \\\\ & D_1,D_2,D_3,D_4,D_5 = 6,6,3,3,3 \end{align}$$
+$$\begin{align}   & D_1,D_2,D_3,D_4,D_5 = 4,3,6,3,5 \\\\
+  & D_1,D_2,D_3,D_4,D_5 = 4,3,3,5,6 \\\\   & D_1,D_2,D_3,D_4,D_5 = 3,3,3,6,6 \\\\
+  & D_1,D_2,D_3,D_4,D_5 = 6,6,3,3,3 \end{align}$$
 
 Якщо кинути двадцять 12-гранних кубиків (грані пронумеровано від 1 до 12), у скількох випадках сума десятьох найбільших чисел дорівнюватиме 70?
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-244-sliders.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-244-sliders.md
index 059111011a..6b92f78d9f 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-244-sliders.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-244-sliders.md
@@ -16,7 +16,9 @@ dashedName: problem-244-sliders
 
 Для кожного шляху його контрольна сума обчислюється так (псевдокод):
 
-$$\begin{align} & \text{checksum} = 0 \\\\ & \text{checksum} = (\text{checksum} × 243 + m_1) \\; \text{mod} \\; 100\\,000\\,007 \\\\ & \text{checksum} = (\text{checksum} × 243 + m_2) \\; \text{mod} \\; 100\\,000\\,007 \\\\ & \ldots \\\\ & \text{checksum} = (\text{checksum} × 243 + m_n) \\; \text{mod} \\; 100\\,000\\,007 \end{align}$$
+$$\begin{align}   & \text{checksum} = 0 \\\\
+  & \text{checksum} = (\text{checksum} × 243 + m_1) \\; \text{mod} \\; 100\\,000\\,007 \\\\   & \text{checksum} = (\text{checksum} × 243 + m_2) \\; \text{mod} \\; 100\\,000\\,007 \\\\
+  & \ldots \\\\ & \text{checksum} = (\text{checksum} × 243 + m_n) \\; \text{mod} \\; 100\\,000\\,007 \end{align}$$
 
 де $m_k$ — ASCII код букви $k^{\text{th}}$ в послідовності ходів. Ось ASCII коди для ходів:
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-252-convex-holes.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-252-convex-holes.md
index 4814814f47..0647abaabf 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-252-convex-holes.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-252-convex-holes.md
@@ -16,7 +16,8 @@ dashedName: problem-252-convex-holes
 
 Наприклад, ми використали перші 20 точок ($T_{2k − 1}$, $T_{2k}$), для $k = 1, 2, \ldots, 20$, отриманих за допомогою генератора псевдовипадкових чисел:
 
-$$\begin{align} S_0 & = 290\\,797 \\\\ S_{n+1} & = {S_n}^2 \\; \text{mod} \\; 50\\,515\\,093 \\\\ T_n & = (S_n \\; \text{mod} \\; 2000) − 1000 \end{align}$$
+$$\begin{align}   S_0 & = 290\\,797 \\\\
+  S_{n+1} & = {S_n}^2 \\; \text{mod} \\; 50\\,515\\,093 \\\\ T_n & = (S_n \\; \text{mod} \\; 2000) − 1000 \end{align}$$
 
 тобто (527, 144), (−488, 732), (−454, −947), …
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-255-rounded-square-roots.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-255-rounded-square-roots.md
index b0bf4ad202..b155a5cf99 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-255-rounded-square-roots.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-255-rounded-square-roots.md
@@ -28,7 +28,8 @@ $$x_{k + 1} = \left\lfloor\frac{x_k + \left\lceil\frac{n}{x_k}\right\rceil}{2}\r
 
 $n$ складається з 4 цифр, тож $x_0 = 7 × {10}^{\frac{4-2}{2}} = 70$.
 
-$$x_1 = \left\lfloor\frac{70 + \left\lceil\frac{4321}{70}\right\rceil}{2}\right\rfloor = 66 \\\\ x_2 = \left\lfloor\frac{66 + \left\lceil\frac{4321}{66}\right\rceil}{2}\right\rfloor = 66$$
+$$x_1 = \left\lfloor\frac{70 + \left\lceil\frac{4321}{70}\right\rceil}{2}\right\rfloor = 66 \\\\
+x_2 = \left\lfloor\frac{66 + \left\lceil\frac{4321}{66}\right\rceil}{2}\right\rfloor = 66$$
 
 Оскільки $x_2 = x_1$, тут зупиняємося. Таким чином, після всього двох ітерацій, ми виявили, що округлений квадратний корінь 4321 дорівнює 66 (точне значення квадратного кореня — 65,7343137...).
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-261-pivotal-square-sums.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-261-pivotal-square-sums.md
index d0a4eb147c..673f110001 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-261-pivotal-square-sums.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-261-pivotal-square-sums.md
@@ -14,7 +14,9 @@ $${(k - m)}^2 + \ldots + k^2 = {(n + 1)}^2 + \ldots + {(n + m)}^2$$
 
 Деякі маленькі квадратні повороти є
 
-$$\begin{align} & \mathbf{4}: 3^2 + \mathbf{4}^2 = 5^2 \\\\ & \mathbf{21}: {20}^2 + \mathbf{21}^2 = {29}^2 \\\\ & \mathbf{24}: {21}^2 + {22}^2 + {23}^2 + \mathbf{24}^2 = {25}^2 + {26}^2 + {27}^2 \\\\ & \mathbf{110}: {108}^2 + {109}^2 + \mathbf{110}^2 = {133}^2 + {134}^2 \\\\ \end{align}$$
+$$\begin{align}   & \mathbf{4}: 3^2 + \mathbf{4}^2 = 5^2 \\\\
+  & \mathbf{21}: {20}^2 + \mathbf{21}^2 = {29}^2 \\\\   & \mathbf{24}: {21}^2 + {22}^2 + {23}^2 + \mathbf{24}^2 = {25}^2 + {26}^2 + {27}^2 \\\\
+  & \mathbf{110}: {108}^2 + {109}^2 + \mathbf{110}^2 = {133}^2 + {134}^2 \\\\ \end{align}$$
 
 Знайдіть суму всіх різних квадратних куточків $≤ {10}^{10}$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-282-the-ackermann-function.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-282-the-ackermann-function.md
index 43fb07bcd3..68d5c163ce 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-282-the-ackermann-function.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-282-the-ackermann-function.md
@@ -10,7 +10,8 @@ dashedName: problem-282-the-ackermann-function
 
 Для невід'ємних цілих $m$, $n$ функція Акермана $A(m, n)$ визначається таким чином:
 
-$$A(m, n) = \begin{cases} n + 1                 & \text{if $m = 0$}             \\\\ A(m - 1, 1)           & \text{if $m > 0$ and $n = 0$} \\\\ A(m - 1, A(m, n - 1)) & \text{if $m > 0$ and $n > 0$} \end{cases}$$
+$$A(m, n) = \begin{cases} n + 1                 & \text{if $m = 0$}             \\\\
+A(m - 1, 1)           & \text{if $m > 0$ and $n = 0$} \\\\ A(m - 1, A(m, n - 1)) & \text{if $m > 0$ and $n > 0$} \end{cases}$$
 
 Наприклад, $A(1, 0) = 2$, $A(2, 2) = 7$ and $A(3, 4) = 125$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-288-an-enormous-factorial.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-288-an-enormous-factorial.md
index 6874c0487a..e224b8264e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-288-an-enormous-factorial.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-288-an-enormous-factorial.md
@@ -10,7 +10,8 @@ dashedName: problem-288-an-enormous-factorial
 
 Для будь-якого цілого числа $p$ число $N(p,q)$ визначається за $N(p,q) = \sum_{n=0}^q T_n \times p^n$ з $T_n$, що створене генератором випадкових чисел:
 
-$$\begin{align} & S_0 = 290797 \\\\ & S_{n + 1} = {S_n}^2\bmod 50\\,515\\,093 \\\\ & T_n = S_n\bmod p \end{align}$$
+$$\begin{align}   & S_0 = 290797 \\\\
+  & S_{n + 1} = {S_n}^2\bmod 50\\,515\\,093 \\\\ & T_n = S_n\bmod p \end{align}$$
 
 Припустимо, $Nfac(p,q)$ – факторіал $N(p,q)$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-295-lenticular-holes.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-295-lenticular-holes.md
index a3b6cec3d5..20b45b5fbb 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-295-lenticular-holes.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-295-lenticular-holes.md
@@ -16,7 +16,8 @@ dashedName: problem-295-lenticular-holes
 
 Розглянемо ці кола:
 
-$$\begin{align} & C_0: x^2 + y^2 = 25 \\\\ & C_1: {(x + 4)}^2 + {(y - 4)}^2 = 1 \\\\ & C_2: {(x - 12)}^2 + {(y - 4)}^2 = 65 \end{align}$$
+$$\begin{align}   & C_0: x^2 + y^2 = 25 \\\\
+  & C_1: {(x + 4)}^2 + {(y - 4)}^2 = 1 \\\\ & C_2: {(x - 12)}^2 + {(y - 4)}^2 = 65 \end{align}$$
 
 Кола $C_0$, $C_1$ та $C_2$ намальовані на малюнку нижче.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-312-cyclic-paths-on-sierpiski-graphs.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-312-cyclic-paths-on-sierpiski-graphs.md
index 7929d3a23d..5c419e3c6e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-312-cyclic-paths-on-sierpiski-graphs.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-312-cyclic-paths-on-sierpiski-graphs.md
@@ -19,7 +19,9 @@ dashedName: problem-312-cyclic-paths-on-sierpiski-graphs
 
 Також можна перевірити, що:
 
-$$\begin{align} & C(1) = C(2) = 1 \\\\ & C(5) = 71\\,328\\,803\\,586\\,048 \\\\ & C(10 000)\bmod {10}^8 = 37\\,652\\,224 \\\\ & C(10 000)\bmod {13}^8 = 617\\,720\\,485 \\\\ \end{align}$$
+$$\begin{align}   & C(1) = C(2) = 1 \\\\
+  & C(5) = 71\\,328\\,803\\,586\\,048 \\\\   & C(10 000)\bmod {10}^8 = 37\\,652\\,224 \\\\
+  & C(10 000)\bmod {13}^8 = 617\\,720\\,485 \\\\ \end{align}$$
 
 Знайдіть $C(C(C(10\\,000)))\bmod {13}^8$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-318-2011-nines.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-318-2011-nines.md
index 397705db4a..2800e34773 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-318-2011-nines.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-318-2011-nines.md
@@ -12,7 +12,11 @@ dashedName: problem-318-2011-nines
 
 Коли ми обчислимо парні степені $\sqrt{2} + \sqrt{3}$, ми отримаємо:
 
-$$\begin{align} & {(\sqrt{2} + \sqrt{3})}^2 = 9.898979485566356\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^4 = 97.98979485566356\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^6 = 969.998969071069263\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^8 = 9601.99989585502907\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^{10} = 95049.999989479221\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^{12} = 940897.9999989371855\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^{14} = 9313929.99999989263\ldots \\\\ & {(\sqrt{2} + \sqrt{3})}^{16} = 92198401.99999998915\ldots \\\\ \end{align}$$
+$$\begin{align}   & {(\sqrt{2} + \sqrt{3})}^2 = 9.898979485566356\ldots \\\\
+  & {(\sqrt{2} + \sqrt{3})}^4 = 97.98979485566356\ldots \\\\   & {(\sqrt{2} + \sqrt{3})}^6 = 969.998969071069263\ldots \\\\
+  & {(\sqrt{2} + \sqrt{3})}^8 = 9601.99989585502907\ldots \\\\   & {(\sqrt{2} + \sqrt{3})}^{10} = 95049.999989479221\ldots \\\\
+  & {(\sqrt{2} + \sqrt{3})}^{12} = 940897.9999989371855\ldots \\\\   & {(\sqrt{2} + \sqrt{3})}^{14} = 9313929.99999989263\ldots \\\\
+  & {(\sqrt{2} + \sqrt{3})}^{16} = 92198401.99999998915\ldots \\\\ \end{align}$$
 
 Схоже, що кількість послідовних дев'яток на початку дробової частини цих ступенів не зменшується. Насправді, можна довести, що дробова частина ${(\sqrt{2} + \sqrt{3})}^{2n}$ наближається до 1 для великого значення $n$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-324-building-a-tower.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-324-building-a-tower.md
index e80c325c89..bed7dfb8bf 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-324-building-a-tower.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-324-building-a-tower.md
@@ -12,7 +12,9 @@ dashedName: problem-324-building-a-tower
 
 Наприклад, (з $q = 100\\,000\\,007$):
 
-$$\begin{align} & f(2) = 229, \\\\ & f(4) = 117\\,805, \\\\ & f(10)\bmod q = 96\\,149\\,360, \\\\ & f({10}^3)\bmod q = 24\\,806\\,056, \\\\ & f({10}^6)\bmod q = 30\\,808\\,124. \end{align}$$
+$$\begin{align}   & f(2) = 229, \\\\
+  & f(4) = 117\\,805, \\\\   & f(10)\bmod q = 96\\,149\\,360, \\\\
+  & f({10}^3)\bmod q = 24\\,806\\,056, \\\\ & f({10}^6)\bmod q = 30\\,808\\,124. \end{align}$$
 
 Знайдіть $f({10}^{10000})\bmod 100\\,000\\,007$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-330-eulers-number.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-330-eulers-number.md
index 6df0d4bb6d..4476edbe0e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-330-eulers-number.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-330-eulers-number.md
@@ -10,11 +10,13 @@ dashedName: problem-330-eulers-number
 
 Нескінченна послідовність дійсних чисел $a(n)$ визначається для усіх цілих чисел $n$ наступним чином:
 
-$$ a(n) = \begin{cases} 1                                                       & n < 0 \\\\ \displaystyle \sum_{i = 1}^{\infty} \frac{a(n - 1)}{i!} & n \ge 0 \end{cases} $$
+$$ a(n) = \begin{cases} 1                                                       & n < 0 \\\\
+\displaystyle \sum_{i = 1}^{\infty} \frac{a(n - 1)}{i!} & n \ge 0 \end{cases} $$
 
 Наприклад,
 
-$$\begin{align} & a(0) = \frac{1}{1!} + \frac{1}{2!} + \frac{1}{3!} + \ldots = e − 1 \\\\ & a(1) = \frac{e − 1}{1!} + \frac{1}{2!} + \frac{1}{3!} + \ldots = 2e − 3 \\\\ & a(2) = \frac{2e − 3}{1!} + \frac{e − 1}{2!} + \frac{1}{3!} + \ldots = \frac{7}{2} e − 6 \end{align}$$
+$$\begin{align}   & a(0) = \frac{1}{1!} + \frac{1}{2!} + \frac{1}{3!} + \ldots = e − 1 \\\\
+  & a(1) = \frac{e − 1}{1!} + \frac{1}{2!} + \frac{1}{3!} + \ldots = 2e − 3 \\\\ & a(2) = \frac{2e − 3}{1!} + \frac{e − 1}{2!} + \frac{1}{3!} + \ldots = \frac{7}{2} e − 6 \end{align}$$
 
 де $e = 2.7182818\ldots$ — число Ейлера.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-333-special-partitions.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-333-special-partitions.md
index ed123b66ad..4cf291ad1e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-333-special-partitions.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-333-special-partitions.md
@@ -14,7 +14,8 @@ dashedName: problem-333-special-partitions
 
 Для багатьох цілих чисел існує декілька варіантів допустимого поділу, починаючи з 11, котре має два шляхи ділення.
 
-$$\begin{align} & 11 = 2 + 9 = (2^1 \times 3^0 + 2^0 \times 3^2) \\\\ & 11 = 8 + 3 = (2^3 \times 3^0 + 2^0 \times 3^1) \end{align}$$
+$$\begin{align}   & 11 = 2 + 9 = (2^1 \times 3^0 + 2^0 \times 3^2) \\\\
+  & 11 = 8 + 3 = (2^3 \times 3^0 + 2^0 \times 3^1) \end{align}$$
 
 Визначимо $P(n)$ як сукупність правильних поділів $n$. Наприклад, $P(11) = 2$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-334-spilling-the-beans.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-334-spilling-the-beans.md
index 67080923b7..3869a22829 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-334-spilling-the-beans.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-334-spilling-the-beans.md
@@ -16,7 +16,10 @@ dashedName: problem-334-spilling-the-beans
 
 Вам надано наступні послідовності:
 
-$$\begin{align} & t_0 = 123456, \\\\ & t_i = \begin{cases} \frac{t_{i - 1}}{2},               & \text{if $t_{i - 1}$ is even} \\\\ \left\lfloor\frac{t_{i - 1}}{2}\right\rfloor \oplus 926252, & \text{if $t_{i - 1}$ is odd} \end{cases} \\\\ & \qquad \text{where $⌊x⌋$ is the floor function and $\oplus$ is the bitwise XOR operator.} \\\\ & b_i = (t_i\bmod 2^{11}) + 1. \end{align}$$
+$$\begin{align}   & t_0 = 123456, \\\\
+  & t_i = \begin{cases}          \frac{t_{i - 1}}{2},               & \text{if $t_{i - 1}$ is even} \\\\
+         \left\lfloor\frac{t_{i - 1}}{2}\right\rfloor \oplus 926252, & \text{if $t_{i - 1}$ is odd}          \end{cases} \\\\
+         & \qquad \text{where $⌊x⌋$ is the floor function and $\oplus$ is the bitwise XOR operator.} \\\\ & b_i = (t_i\bmod 2^{11}) + 1. \end{align}$$
 
 Перші дві умови останньої послідовності: $b_1 = 289$ and $b_2 = 145$. Якщо б ми почали з $b_1$ і $b_2$ бобів у двох сусідніх мисках, то нам потрібно було б 3419100 кроків, щоб завершити гру.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-340-crazy-function.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-340-crazy-function.md
index ab19d2d271..87d7962b01 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-340-crazy-function.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-340-crazy-function.md
@@ -10,7 +10,8 @@ dashedName: problem-340-crazy-function
 
 Для фіксованих цілих $a$, $b$, $c$ визначити цю функцію $F(n)$ наступним чином:
 
-$$\begin{align} & F(n) = n - c \\;\text{ for all } n > b \\\\ & F(n) = F(a + F(a + F(a + F(a + n)))) \\;\text{ for all } n ≤ b. \end{align}$$
+$$\begin{align}   & F(n) = n - c \\;\text{ for all } n > b \\\\
+  & F(n) = F(a + F(a + F(a + F(a + n)))) \\;\text{ for all } n ≤ b. \end{align}$$
 
 Також визначте $S(a, b, c) = \displaystyle\sum_{n = 0}^b F(n)$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-341-golombs-self-describing-sequence.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-341-golombs-self-describing-sequence.md
index 21175fada6..7aca141d49 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-341-golombs-self-describing-sequence.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-341-golombs-self-describing-sequence.md
@@ -10,7 +10,8 @@ dashedName: problem-341-golombs-self-describing-sequence
 
 Послідовність Голомба ($G(n)$) є єдиною незменшувальною послідовність натуральних чисел, така що $n$ з'являється рівно $G(n)$ разів у послідовності. Значення $G(n)$ для перших кількох $n$ є
 
-$$\початок{array}{c} n    & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & 13 & 14 & 15 & \ldots \\\\ G(n) & 1 & 2 & 2 & 3 & 3 & 4 & 4 & 4 & 5 & 5  &  5 &  6 &  6 &  6 &  6 & \ldots \end{array}$$
+$$\початок{array}{c}   n    & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & 13 & 14 & 15 & \ldots \\\\
+  G(n) & 1 & 2 & 2 & 3 & 3 & 4 & 4 & 4 & 5 & 5  &  5 &  6 &  6 &  6 &  6 & \ldots \end{array}$$
 
 Вам дано що $G({10}^3) = 86$, $G({10}^6) = 6137$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-345-matrix-sum.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-345-matrix-sum.md
index c72f261899..a6ba7dabe7 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-345-matrix-sum.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-345-matrix-sum.md
@@ -12,11 +12,20 @@ dashedName: problem-345-matrix-sum
 
 Наприклад, матрична сума матриці нижче дорівнює $3315 ( = 863 + 383 + 343 + 959 + 767)$:
 
-$$\begin{array}{rrrrr} 7                &  53                & 183                & 439                & \color{lime}{863} \\\\ 497                & \color{lime}{383} & 563                &  79                & 973 \\\\ 287                &  63                & \color{lime}{343} & 169                & 583 \\\\ 627                & 343                & 773                & \color{lime}{959} & 943 \\\\ \color{lime}{767} & 473                & 103                & 699                & 303 \end{array}$$
+$$\begin{array}{rrrrr}     7                &  53                & 183                & 439                & \color{lime}{863} \\\\
+  497                & \color{lime}{383} & 563                &  79                & 973 \\\\   287                &  63                & \color{lime}{343} & 169                & 583 \\\\
+  627                & 343                & 773                & \color{lime}{959} & 943 \\\\ \color{lime}{767} & 473                & 103                & 699                & 303 \end{array}$$
 
 Знайдіть матричну суму матриці:
 
-$$\\begin{array}{r} 7 &  53 & 183 & 439 & 863 & 497 & 383 & 563 &  79 & 973 & 287 &  63 & 343 & 169 & 583 \\\\ 627 & 343 & 773 & 959 & 943 & 767 & 473 & 103 & 699 & 303 & 957 & 703 & 583 & 639 & 913 \\\\ 447 & 283 & 463 &  29 &  23 & 487 & 463 & 993 & 119 & 883 & 327 & 493 & 423 & 159 & 743 \\\\ 217 & 623 &   3 & 399 & 853 & 407 & 103 & 983 &  89 & 463 & 290 & 516 & 212 & 462 & 350 \\\\ 960 & 376 & 682 & 962 & 300 & 780 & 486 & 502 & 912 & 800 & 250 & 346 & 172 & 812 & 350 \\\\ 870 & 456 & 192 & 162 & 593 & 473 & 915 &  45 & 989 & 873 & 823 & 965 & 425 & 329 & 803 \\\\ 973 & 965 & 905 & 919 & 133 & 673 & 665 & 235 & 509 & 613 & 673 & 815 & 165 & 992 & 326 \\\\ 322 & 148 & 972 & 962 & 286 & 255 & 941 & 541 & 265 & 323 & 925 & 281 & 601 &  95 & 973 \\\\ 445 & 721 &  11 & 525 & 473 &  65 & 511 & 164 & 138 & 672 &  18 & 428 & 154 & 448 & 848 \\\\ 414 & 456 & 310 & 312 & 798 & 104 & 566 & 520 & 302 & 248 & 694 & 976 & 430 & 392 & 198 \\\\ 184 & 829 & 373 & 181 & 631 & 101 & 969 & 613 & 840 & 740 & 778 & 458 & 284 & 760 & 390 \\\\ 821 & 461 & 843 & 513 &  17 & 901 & 711 & 993 & 293 & 157 & 274 &  94 & 192 & 156 & 574 \\\\ 34 & 124 &   4 & 878 & 450 & 476 & 712 & 914 & 838 & 669 & 875 & 299 & 823 & 329 & 699 \\\\ 815 & 559 & 813 & 459 & 522 & 788 & 168 & 586 & 966 & 232 & 308 & 833 & 251 & 631 & 107 \\\\ 813 & 883 & 451 & 509 & 615 &  77 & 281 & 613 & 459 & 205 & 380 & 274 & 302 &  35 & 805 \end{array}$$
+$$\\begin{array}{r}     7 &  53 & 183 & 439 & 863 & 497 & 383 & 563 &  79 & 973 & 287 &  63 & 343 & 169 & 583 \\\\
+  627 & 343 & 773 & 959 & 943 & 767 & 473 & 103 & 699 & 303 & 957 & 703 & 583 & 639 & 913 \\\\   447 & 283 & 463 &  29 &  23 & 487 & 463 & 993 & 119 & 883 & 327 & 493 & 423 & 159 & 743 \\\\
+  217 & 623 &   3 & 399 & 853 & 407 & 103 & 983 &  89 & 463 & 290 & 516 & 212 & 462 & 350 \\\\   960 & 376 & 682 & 962 & 300 & 780 & 486 & 502 & 912 & 800 & 250 & 346 & 172 & 812 & 350 \\\\
+  870 & 456 & 192 & 162 & 593 & 473 & 915 &  45 & 989 & 873 & 823 & 965 & 425 & 329 & 803 \\\\   973 & 965 & 905 & 919 & 133 & 673 & 665 & 235 & 509 & 613 & 673 & 815 & 165 & 992 & 326 \\\\
+  322 & 148 & 972 & 962 & 286 & 255 & 941 & 541 & 265 & 323 & 925 & 281 & 601 &  95 & 973 \\\\   445 & 721 &  11 & 525 & 473 &  65 & 511 & 164 & 138 & 672 &  18 & 428 & 154 & 448 & 848 \\\\
+  414 & 456 & 310 & 312 & 798 & 104 & 566 & 520 & 302 & 248 & 694 & 976 & 430 & 392 & 198 \\\\   184 & 829 & 373 & 181 & 631 & 101 & 969 & 613 & 840 & 740 & 778 & 458 & 284 & 760 & 390 \\\\
+  821 & 461 & 843 & 513 &  17 & 901 & 711 & 993 & 293 & 157 & 274 &  94 & 192 & 156 & 574 \\\\    34 & 124 &   4 & 878 & 450 & 476 & 712 & 914 & 838 & 669 & 875 & 299 & 823 & 329 & 699 \\\\
+  815 & 559 & 813 & 459 & 522 & 788 & 168 & 586 & 966 & 232 & 308 & 833 & 251 & 631 & 107 \\\\ 813 & 883 & 451 & 509 & 615 &  77 & 281 & 613 & 459 & 205 & 380 & 274 & 302 &  35 & 805 \end{array}$$
 
 # --hints--
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-348-sum-of-a-square-and-a-cube.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-348-sum-of-a-square-and-a-cube.md
index 1597ad7a77..c00400163a 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-348-sum-of-a-square-and-a-cube.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-348-sum-of-a-square-and-a-cube.md
@@ -14,7 +14,9 @@ dashedName: problem-348-sum-of-a-square-and-a-cube
 
 Наприклад, 5229225 - це паліндромне число, яке можна записати 4 способами:
 
-$$\begin{align} & {2285}^2 + {20}^3 \\\\ & {2223}^2 + {66}^3 \\\\ & {1810}^2 + {125}^3 \\\\ & {1197}^2 + {156}^3 \end{align}$$
+$$\begin{align}   & {2285}^2 + {20}^3 \\\\
+  & {2223}^2 + {66}^3 \\\\   & {1810}^2 + {125}^3 \\\\
+  & {1197}^2 + {156}^3 \end{align}$$
 
 Знайдіть суму п'яти найменших таких паліндромних чисел.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-350-constraining-the-least-greatest-and-the-greatest-least.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-350-constraining-the-least-greatest-and-the-greatest-least.md
index eea801849b..2fd6823dbc 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-350-constraining-the-least-greatest-and-the-greatest-least.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-350-constraining-the-least-greatest-and-the-greatest-least.md
@@ -16,7 +16,9 @@ dashedName: problem-350-constraining-the-least-greatest-and-the-greatest-least
 
 $f(G, L, N)$ - це кількість списків розміру $N$ з $gcd ≥ G$ та $lcm ≤ L$. Наприклад:
 
-$$\begin{align} & f(10, 100, 1) = 91 \\\\ & f(10, 100, 2) = 327 \\\\ & f(10, 100, 3) = 1135 \\\\ & f(10, 100, 1000)\bmod {101}^4 = 3\\,286\\,053 \end{align}$$
+$$\begin{align}   & f(10, 100, 1) = 91 \\\\
+  & f(10, 100, 2) = 327 \\\\   & f(10, 100, 3) = 1135 \\\\
+  & f(10, 100, 1000)\bmod {101}^4 = 3\\,286\\,053 \end{align}$$
 
 Знайдіть $f({10}^6, {10}^{12}, {10}^{18})\bmod {101}^4$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-358-cyclic-numbers.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-358-cyclic-numbers.md
index 5c9051bcd5..1d9f3869c3 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-358-cyclic-numbers.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-358-cyclic-numbers.md
@@ -14,11 +14,16 @@ dashedName: problem-358-cyclic-numbers
 
 Найменше циклічне число - це 6-значне число 142857:
 
-$$\begin{align} & 142857 × 1 = 142857 \\\\ & 142857 × 2 = 285714 \\\\ & 142857 × 3 = 428571 \\\\ & 142857 × 4 = 571428 \\\\ & 142857 × 5 = 714285 \\\\ & 142857 × 6 = 857142 \end{align}$$
+$$\begin{align}   & 142857 × 1 = 142857 \\\\
+  & 142857 × 2 = 285714 \\\\   & 142857 × 3 = 428571 \\\\
+  & 142857 × 4 = 571428 \\\\   & 142857 × 5 = 714285 \\\\
+  & 142857 × 6 = 857142 \end{align}$$
 
 Наступне циклічне число 0588235294117647 на 16 цифр:
 
-$$\begin{align} & 0588235294117647 × 1 = 0588235294117647 \\\\ & 0588235294117647 × 2 = 1176470588235294 \\\\ & 0588235294117647 × 3 = 1764705882352941 \\\\ & \ldots \\\\ & 0588235294117647 × 16 = 9411764705882352 \end{align}$$
+$$\begin{align}   & 0588235294117647 × 1 = 0588235294117647 \\\\
+  & 0588235294117647 × 2 = 1176470588235294 \\\\   & 0588235294117647 × 3 = 1764705882352941 \\\\
+  & \ldots \\\\ & 0588235294117647 × 16 = 9411764705882352 \end{align}$$
 
 Зауважте, що для циклічних чисел важливі нулі на початку.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-359-hilberts-new-hotel.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-359-hilberts-new-hotel.md
index 60183135ec..644d87c8d9 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-359-hilberts-new-hotel.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-359-hilberts-new-hotel.md
@@ -27,7 +27,10 @@ dashedName: problem-359-hilberts-new-hotel
 
 Визначте $P(f, r)$ як $n$, якщо особа $n$ займає кімнату $r$ на поверсі $f$, та 0, якщо жодна людина не займає кімнату. Ось декілька прикладів:
 
-$$\begin{align} & P(1, 1) = 1 \\\\ & P(1, 2) = 3 \\\\ & P(2, 1) = 2 \\\\ & P(10, 20) = 440 \\\\ & P(25, 75) = 4863 \\\\ & P(99, 100) = 19454 \end{align}$$
+$$\begin{align}   & P(1, 1) = 1 \\\\
+  & P(1, 2) = 3 \\\\   & P(2, 1) = 2 \\\\
+  & P(10, 20) = 440 \\\\   & P(25, 75) = 4863 \\\\
+  & P(99, 100) = 19454 \end{align}$$
 
 Знайти суму усіх $P(f, r)$ для всіх додатних $f$ і $r$, такі як $f × r = 71\\, 28\\,803\\,586\\,048$ і вказати останні 8 цифр як відповідь.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-361-subsequence-of-thue-morse-sequence.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-361-subsequence-of-thue-morse-sequence.md
index 3cb1e7f966..771c4c3ee7 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-361-subsequence-of-thue-morse-sequence.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-361-subsequence-of-thue-morse-sequence.md
@@ -20,7 +20,8 @@ dashedName: problem-361-subsequence-of-thue-morse-sequence
 
 Перші кілька термінів $A_n$ наведені наступним чином:
 
-$$\begin{array}{cr} n   & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 &  8 &  9 & 10 & 11 & 12 & \ldots \\\\ A_n & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 9 & 10 & 11 & 12 & 13 & 18 & \ldots \end{array}$$
+$$\begin{array}{cr}   n   & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 &  8 &  9 & 10 & 11 & 12 & \ldots \\\\
+  A_n & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 9 & 10 & 11 & 12 & 13 & 18 & \ldots \end{array}$$
 
 Ми також можемо підтвердити, що $A_{100} = 3251$ та $A_{1000} = 80\\,852\\,364\\,498$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-368-a-kempner-like-series.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-368-a-kempner-like-series.md
index 35ea0bfb62..4e2da51934 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-368-a-kempner-like-series.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-368-a-kempner-like-series.md
@@ -16,7 +16,8 @@ dashedName: problem-368-a-kempner-like-series
 
 20 опущених значень:
 
-$$\dfrac{1}{111}, \dfrac{1}{222}, \dfrac{1}{333}, \dfrac{1}{444}, \dfrac{1}{555}, \dfrac{1}{666}, \dfrac{1}{777}, \dfrac{1}{888}, \dfrac{1}{999}, \dfrac{1}{1000}, \dfrac{1}{1110}, \\\\ \dfrac{1}{1111}, \dfrac{1}{1112}, \dfrac{1}{1113}, \dfrac{1}{1114}, \dfrac{1}{1115}, \dfrac{1}{1116}, \dfrac{1}{1117}, \dfrac{1}{1118}, \dfrac{1}{1119}$$
+$$\dfrac{1}{111}, \dfrac{1}{222}, \dfrac{1}{333}, \dfrac{1}{444}, \dfrac{1}{555}, \dfrac{1}{666}, \dfrac{1}{777}, \dfrac{1}{888}, \dfrac{1}{999}, \dfrac{1}{1000}, \dfrac{1}{1110}, \\\\
+\dfrac{1}{1111}, \dfrac{1}{1112}, \dfrac{1}{1113}, \dfrac{1}{1114}, \dfrac{1}{1115}, \dfrac{1}{1116}, \dfrac{1}{1117}, \dfrac{1}{1118}, \dfrac{1}{1119}$$
 
 Ця послідовність також сходиться.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-375-minimum-of-subsequences.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-375-minimum-of-subsequences.md
index 6d85b3a676..735983f216 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-375-minimum-of-subsequences.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-375-minimum-of-subsequences.md
@@ -10,7 +10,8 @@ dashedName: problem-375-minimum-of-subsequences
 
 Нехай $S_n$ буде цілочисельною послідовністю, створеною за допомогою такого генератора псевдовипадкових чисел:
 
-$$\begin{align} S_0 & = 290\\,797 \\\\ S_{n + 1} & = {S_n}^2\bmod 50\\,515\\,093 \end{align}$$
+$$\begin{align}         S_0 & = 290\\,797 \\\\
+  S_{n + 1} & = {S_n}^2\bmod 50\\,515\\,093 \end{align}$$
 
 Нехай $A(i, j)$ буде мінімальним з чисел $S_i, S_{i + 1}, \ldots, S_j$ for $i ≤ j$. Нехай $M(N) = \sum A(i, j)$ для $1 ≤ i ≤ j ≤ N$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-376-nontransitive-sets-of-dice.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-376-nontransitive-sets-of-dice.md
index 8394ab0439..4ef0cab00a 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-376-nontransitive-sets-of-dice.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-376-nontransitive-sets-of-dice.md
@@ -10,7 +10,9 @@ dashedName: problem-376-nontransitive-sets-of-dice
 
 Розглянемо такий набір кубиків з нетиповою розміткою:
 
-$$\begin{array}{} \text{Die A: } & 1 & 4 & 4 & 4 & 4 & 4 \\\\ \text{Die B: } & 2 & 2 & 2 & 5 & 5 & 5 \\\\ \text{Die C: } & 3 & 3 & 3 & 3 & 3 & 6 \\\\ \end{array}$$
+$$\begin{array}{}   \text{Die A: } & 1 & 4 & 4 & 4 & 4 & 4 \\\\
+  \text{Die B: } & 2 & 2 & 2 & 5 & 5 & 5 \\\\   \text{Die C: } & 3 & 3 & 3 & 3 & 3 & 6 \\\\
+\end{array}$$
 
 За правилами гри, двоє гравців по черзі підкидують гральний кубик. Переможцем стає той, чий кубик показав найвище значення.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-38-pandigital-multiples.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-38-pandigital-multiples.md
index 81b8adf5b1..7c2ae028e5 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-38-pandigital-multiples.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-38-pandigital-multiples.md
@@ -10,7 +10,9 @@ dashedName: problem-38-pandigital-multiples
 
 Візьміть число 192 і помножте його на 1, 2 і 3:
 
-$$\begin{align} 192 × 1 = 192\\\\ 192 × 2 = 384\\\\ 192 × 3 = 576\\\\ \end{align}$$
+$$\begin{align}   192 × 1 = 192\\\\
+  192 × 2 = 384\\\\   192 × 3 = 576\\\\
+\end{align}$$
 
 Об'єднавши кожний добуток, ми отримаємо панцифрове число від 1 до 9 - 192384576. Назвемо отримане число 192384576 об'єднаним добутком 192 і (1, 2, 3).
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-384-rudin-shapiro-sequence.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-384-rudin-shapiro-sequence.md
index 50caf1667e..68d2b0bab8 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-384-rudin-shapiro-sequence.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-384-rudin-shapiro-sequence.md
@@ -18,7 +18,9 @@ dashedName: problem-384-rudin-shapiro-sequence
 
 Перші декілька значень цих послідовностей:
 
-$$\begin{array}{lr} n    & 0 & 1 & 2 &  3 & 4 & 5 &  6 & 7 \\\\ a(n) & 0 & 0 & 0 &  1 & 0 & 0 &  1 & 2 \\\\ b(n) & 1 & 1 & 1 & -1 & 1 & 1 & -1 & 1 \\\\ s(n) & 1 & 2 & 3 &  2 & 3 & 4 &  3 & 4 \end{array}$$
+$$\begin{array}{lr}   n    & 0 & 1 & 2 &  3 & 4 & 5 &  6 & 7 \\\\
+  a(n) & 0 & 0 & 0 &  1 & 0 & 0 &  1 & 2 \\\\   b(n) & 1 & 1 & 1 & -1 & 1 & 1 & -1 & 1 \\\\
+  s(n) & 1 & 2 & 3 &  2 & 3 & 4 &  3 & 4 \end{array}$$
 
 Послідовність $s(n)$ має особливу властивість, коли усі її елементи позитивні, а кожне позитивне ціле число $k$ виникає рівно $k$ разів.
 
@@ -28,7 +30,8 @@ $$\begin{array}{lr} n    & 0 & 1 & 2 &  3 & 4 & 5 &  6 & 7 \\\\ a(n) & 0 & 0 & 0
 
 Нехай $F(n)$ буде послідовністю Фібоначчі, що визначається наступним:
 
-$$\begin{align} & F(0) = F(1) = 1 \text{ and} \\\\ & F(n) = F(n - 1) + F(n - 2) \text{ for } n > 1. \end{align}$$
+$$\begin{align}   & F(0) = F(1) = 1 \text{ and} \\\\
+  & F(n) = F(n - 1) + F(n - 2) \text{ for } n > 1. \end{align}$$
 
 Визначити $GF(t) = g(F(t), F(t - 1))$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-406-guessing-game.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-406-guessing-game.md
index 601fd43213..dd420101ac 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-406-guessing-game.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-406-guessing-game.md
@@ -32,7 +32,9 @@ dashedName: problem-406-guessing-game
 
 Ось декілька прикладів:
 
-$$\begin{align} & C(5, 2, 3) = 5 \\\\ & C(500, \sqrt{2}, \sqrt{3}) = 13.220\\,731\\,97\ldots \\\\ & C(20\\,000, 5, 7) = 82 \\\\ & C(2\\,000\\,000, √5, √7) = 49.637\\,559\\,55\ldots \\\\ \end{align}$$
+$$\begin{align}   & C(5, 2, 3) = 5 \\\\
+  & C(500, \sqrt{2}, \sqrt{3}) = 13.220\\,731\\,97\ldots \\\\   & C(20\\,000, 5, 7) = 82 \\\\
+  & C(2\\,000\\,000, √5, √7) = 49.637\\,559\\,55\ldots \\\\ \end{align}$$
 
 Нехай $F_k$ буде цифрами фібоначчі: $F_k = F_{k - 1} + F_{k - 2}$ з базовими кешами $F_1 = F_2 = 1$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-414-kaprekar-constant.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-414-kaprekar-constant.md
index b7cd690949..00d7107ebc 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-414-kaprekar-constant.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-414-kaprekar-constant.md
@@ -16,7 +16,8 @@ dashedName: problem-414-kaprekar-constant
 
 Наприклад, почнемо з числа 0837:
 
-$$\begin{align} & 8730 - 0378 = 8352 \\\\ & 8532 - 2358 = 6174 \end{align}$$
+$$\begin{align}   & 8730 - 0378 = 8352 \\\\
+  & 8532 - 2358 = 6174 \end{align}$$
 
 6174 називається сталою Капрекара. Сортування цифр, віднімання та повторення цього процесу поки не отримаємо 0 або сталу Капрекара, називається перетворенням Капрекара.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-417-reciprocal-cycles-ii.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-417-reciprocal-cycles-ii.md
index b876586ecc..e04a5bef95 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-417-reciprocal-cycles-ii.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-417-reciprocal-cycles-ii.md
@@ -10,7 +10,12 @@ dashedName: problem-417-reciprocal-cycles-ii
 
 Одиничний дріб містить 1 в чисельнику. Десяткове представлення дробів зі знаменниками від 2 до 10:
 
-$$\begin{align} & \frac{1}{2}  = 0.5 \\\\ & \frac{1}{3}  = 0.(3) \\\\ & \frac{1}{4}  = 0.25 \\\\ & \frac{1}{5}  = 0.2 \\\\ & \frac{1}{6}  = 0.1(6) \\\\ & \frac{1}{7}  = 0.(142857) \\\\ & \frac{1}{8}  = 0.125 \\\\ & \frac{1}{9}  = 0.(1) \\\\ & \frac{1}{10} = 0.1 \\\\ \end{align}$$
+$$\begin{align}   & \frac{1}{2}  = 0.5 \\\\
+  & \frac{1}{3}  = 0.(3) \\\\   & \frac{1}{4}  = 0.25 \\\\
+  & \frac{1}{5}  = 0.2 \\\\   & \frac{1}{6}  = 0.1(6) \\\\
+  & \frac{1}{7}  = 0.(142857) \\\\   & \frac{1}{8}  = 0.125 \\\\
+  & \frac{1}{9}  = 0.(1) \\\\   & \frac{1}{10} = 0.1 \\\\
+\end{align}$$
 
 Де 0.1(6) означає 0.166666... і має послідовність з однієї цифри, що повторюється. Бачимо, що $\frac{1}{7}$ має послідовність із 6 цифр, що повторюються.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-420-2x2-positive-integer-matrix.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-420-2x2-positive-integer-matrix.md
index 2348769803..758f3dbc84 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-420-2x2-positive-integer-matrix.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-420-2x2-positive-integer-matrix.md
@@ -12,11 +12,14 @@ dashedName: problem-420-2x2-positive-integer-matrix
 
 Деякі матриці натуральних чисел можуть бути виражені у вигляді квадрата матриці натуральних чисел двома різними способами. Наприклад:
 
-$$\begin{pmatrix} 40 & 12 \\\\ 48 & 40 \end{pmatrix} =
+$$\begin{pmatrix}   40 & 12 \\\\
+  48 & 40 \end{pmatrix} =
 {\begin{pmatrix}
-  2 & 3 \\\\ 12 & 2 \end{pmatrix}}^2 =
+  2 & 3 \\\\
+ 12 & 2 \end{pmatrix}}^2 =
 {\begin{pmatrix}
-  6 & 1 \\\\ 4 & 6 \end{pmatrix}}^2$$
+  6 & 1 \\\\
+  4 & 6 \end{pmatrix}}^2$$
 
 Визначаємо $F (N)$ як кількість матриць натуральних чисел 2x2, які мають слід менше N, і які можуть бути виражені у вигляді квадрата натурального числа матриці двома різними способами.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-423-consecutive-die-throws.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-423-consecutive-die-throws.md
index 45ed51aedc..f86109169f 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-423-consecutive-die-throws.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-423-consecutive-die-throws.md
@@ -14,7 +14,8 @@ dashedName: problem-423-consecutive-die-throws
 
 Наприклад, якщо $n = 7$ і значення кидків кубика є (1, 5, 6, 6, 6, 3), тоді наступні кидки поспіль дають однакове значення:
 
-$$\begin{align} & (\underline{1}, \underline{1}, 5, 6, 6, 6, 3) \\\\ & (1, 1, 5, \underline{6}, \underline{6}, 6, 3) \\\\ & (1, 1, 5, 6, \underline{6}, \underline{6}, 3) \end{align}$$
+$$\begin{align}   & (\underline{1}, \underline{1}, 5, 6, 6, 6, 3) \\\\
+  & (1, 1, 5, \underline{6}, \underline{6}, 6, 3) \\\\ & (1, 1, 5, 6, \underline{6}, \underline{6}, 3) \end{align}$$
 
 Таким чином, $c = 3$ за (1, 5, 6, 6, 3).
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-426-box-ball-system.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-426-box-ball-system.md
index e842f11bd3..2828758f6e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-426-box-ball-system.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-426-box-ball-system.md
@@ -24,7 +24,8 @@ dashedName: problem-426-box-ball-system
 
 Ми визначили послідовність $\\{t_i\\}$:
 
-$$\begin{align} & s_0 = 290\\,797 \\\\ & s_{k + 1} = {s_k}^2\bmod 50\\,515\\,093 \\\\ & t_k = (s_k\bmod 64) + 1 \end{align}$$
+$$\begin{align}   & s_0 = 290\\,797 \\\\
+  & s_{k + 1} = {s_k}^2\bmod 50\\,515\\,093 \\\\ & t_k = (s_k\bmod 64) + 1 \end{align}$$
 
 Починаючи з початкової конфігурації $(t_0, t_1, \ldots, t_{10})$, кінцевим станом стане [1, 3, 10, 24, 51, 75].
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-433-steps-in-euclids-algorithm.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-433-steps-in-euclids-algorithm.md
index 09fd73b93d..5a9a4f818e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-433-steps-in-euclids-algorithm.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-433-steps-in-euclids-algorithm.md
@@ -10,7 +10,8 @@ dashedName: problem-433-steps-in-euclids-algorithm
 
 Нехай $E(x_0, y_0)$ є кількістю кроків, необхідних для визначення найбільшого спільного дільника для $x_0$ та $y_0$ з алгоритмом Евкліда. Більш формально:
 
-$$\begin{align} & x_1 = y_0, y_1 = x_0\bmod y_0 \\\\ & x_n = y_{n - 1}, y_n = x_{n - 1}\bmod y_{n - 1} \end{align}$$
+$$\begin{align}   & x_1 = y_0, y_1 = x_0\bmod y_0 \\\\
+  & x_n = y_{n - 1}, y_n = x_{n - 1}\bmod y_{n - 1} \end{align}$$
 
 $E(x_0, y_0)$ є найменшим $n$ так, щоб $y_n = 0$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-437-fibonacci-primitive-roots.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-437-fibonacci-primitive-roots.md
index c46c55f740..476994dab5 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-437-fibonacci-primitive-roots.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-437-fibonacci-primitive-roots.md
@@ -16,7 +16,11 @@ dashedName: problem-437-fibonacci-primitive-roots
 
 Якщо розглянути детальніше, то:
 
-$$\begin{align} & 1 + 8 = 9 \\\\ & 8 + 9 = 17 ≡ 6\bmod 11 \\\\ & 9 + 6 = 15 ≡ 4\bmod 11 \\\\ & 6 + 4 = 10 \\\\ & 4 + 10 = 14 ≡ 3\bmod 11 \\\\ & 10 + 3 = 13 ≡ 2\bmod 11 \\\\ & 3 + 2 = 5 \\\\ & 2 + 5 = 7 \\\\ & 5 + 7 = 12 ≡ 1\bmod 11. \end{align}$$
+$$\begin{align}   & 1 + 8 = 9 \\\\
+  & 8 + 9 = 17 ≡ 6\bmod 11 \\\\   & 9 + 6 = 15 ≡ 4\bmod 11 \\\\
+  & 6 + 4 = 10 \\\\   & 4 + 10 = 14 ≡ 3\bmod 11 \\\\
+  & 10 + 3 = 13 ≡ 2\bmod 11 \\\\   & 3 + 2 = 5 \\\\
+  & 2 + 5 = 7 \\\\ & 5 + 7 = 12 ≡ 1\bmod 11. \end{align}$$
 
 Тож степінь з 8 модуля 11 є циклічним в 10 періоді, а $8^n + 8^{n + 1} ≡ 8^{n + 2} (\text{mod } 11)$. Число 8 називають простим коренем Фібоначчі для 11.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-440-gcd-and-tiling.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-440-gcd-and-tiling.md
index 2d7579c1ff..dfded7d455 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-440-gcd-and-tiling.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-440-gcd-and-tiling.md
@@ -24,7 +24,8 @@ dashedName: problem-440-gcd-and-tiling
 
 Наприклад:
 
-$$\begin{align} & S(2) = 10\\,444 \\\\ & S(3) = 1\\,292\\,115\\,238\\,446\\,807\\,016\\,106\\,539\\,989 \\\\ & S(4)\bmod 987\\,898\\,789 = 670\\,616\\,280. \end{align}$$
+$$\begin{align}   & S(2) = 10\\,444 \\\\
+  & S(3) = 1\\,292\\,115\\,238\\,446\\,807\\,016\\,106\\,539\\,989 \\\\ & S(4)\bmod 987\\,898\\,789 = 670\\,616\\,280. \end{align}$$
 
 Знайдіть $S(2000)\bmod 987\\,898\\,789$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-443-gcd-sequence.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-443-gcd-sequence.md
index 1a796d5dd2..6c46b8f856 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-443-gcd-sequence.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-443-gcd-sequence.md
@@ -10,11 +10,13 @@ dashedName: problem-443-gcd-sequence
 
 Нехай $g(n)$ — це послідовність, яка визначається так:
 
-$$\begin{align} & g(4) = 13, \\\\ & g(n) = g(n-1) + gcd(n, g(n - 1)) \text{ for } n > 4. \end{align}$$
+$$\begin{align}   & g(4) = 13, \\\\
+  & g(n) = g(n-1) + gcd(n, g(n - 1)) \text{ for } n > 4. \end{align}$$
 
 Перші кілька значень:
 
-$$\begin{array}{l} n    & 4  & 5  & 6  & 7  & 8  & 9  & 10 & 11 & 12 & 13 & 14 & 15 & 16 & 17 & 18 & 19 & 20 & \ldots \\\\ g(n) & 13 & 14 & 16 & 17 & 18 & 27 & 28 & 29 & 30 & 31 & 32 & 33 & 34 & 51 & 54 & 55 & 60 & \ldots \end{array}$$
+$$\begin{array}{l}   n    & 4  & 5  & 6  & 7  & 8  & 9  & 10 & 11 & 12 & 13 & 14 & 15 & 16 & 17 & 18 & 19 & 20 & \ldots \\\\
+  g(n) & 13 & 14 & 16 & 17 & 18 & 27 & 28 & 29 & 30 & 31 & 32 & 33 & 34 & 51 & 54 & 55 & 60 & \ldots \end{array}$$
 
 Дано, що $g(1\\,000) = 2\\,524$, а $g(1\\,000\\,000) = 2\\,624\\,152$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-451-modular-inverses.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-451-modular-inverses.md
index f47c0a1023..bf54fa9f88 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-451-modular-inverses.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-451-modular-inverses.md
@@ -14,7 +14,10 @@ dashedName: problem-451-modular-inverses
 
 Числа 1, 8, 4, 13, 2, 11, 7, 14 є оберненими за модулем 15, оскільки
 
-$$\begin{align} & 1  \times 1\bmod 15 = 1 \\\\ & 2  \times 8  = 16\bmod 15 = 1 \\\\ & 4  \times 4  = 16\bmod 15 = 1 \\\\ & 7  \times 13 = 91\bmod 15 = 1 \\\\ & 11 \times 11 = 121\bmod 15 = 1 \\\\ & 14 \times 14 = 196\bmod 15 = 1 \end{align}$$
+$$\begin{align}   & 1  \times 1\bmod 15 = 1 \\\\
+  & 2  \times 8  = 16\bmod 15 = 1 \\\\   & 4  \times 4  = 16\bmod 15 = 1 \\\\
+  & 7  \times 13 = 91\bmod 15 = 1 \\\\   & 11 \times 11 = 121\bmod 15 = 1 \\\\
+  & 14 \times 14 = 196\bmod 15 = 1 \end{align}$$
 
 Нехай $I(n)$ — це найбільше додатне число $m$, менше за $n - 1$, при якому обернене за модулем число $m$ з модулем $n$ дорівнює цьому ж числу $m$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-455-powers-with-trailing-digits.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-455-powers-with-trailing-digits.md
index dcf318e5c8..1662bc7b80 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-455-powers-with-trailing-digits.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-455-powers-with-trailing-digits.md
@@ -12,7 +12,9 @@ dashedName: problem-455-powers-with-trailing-digits
 
 Наприклад:
 
-$$\begin{align} & f(4) = 411\\,728\\,896 (4^{411\\,728\\,896} = . ..490\underline{411728896}) \\\\ & f(10) = 0 \\\\ & f(157) = 743\\,757 (157^{743\\,757} = ...567\underline{000743757}) \\\\ & Σf(n), 2 ≤ n ≤ 103 = 442\\,530\\,011\\,399 \end{align}$$
+$$\begin{align} & f(4) = 411\\,728\\,896 (4^{411\\,728\\,896} = . ..490\underline{411728896}) \\\\
+  & f(10) = 0 \\\\   & f(157) = 743\\,757 (157^{743\\,757} = ...567\underline{000743757}) \\\\
+  & Σf(n), 2 ≤ n ≤ 103 = 442\\,530\\,011\\,399 \end{align}$$
 
 Знайдіть $\sum f(n)$, $2 ≤ n ≤ {10}^6$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-456-triangles-containing-the-origin-ii.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-456-triangles-containing-the-origin-ii.md
index 65c4739a0a..e56115ef62 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-456-triangles-containing-the-origin-ii.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-456-triangles-containing-the-origin-ii.md
@@ -10,7 +10,8 @@ dashedName: problem-456-triangles-containing-the-origin-ii
 
 Визначте:
 
-$$\begin{align} & x_n = ({1248}^n\bmod 32323) - 16161 \\\\ & y_n = ({8421}^n\bmod 30103) - 15051 \\\\ & P_n = \\{(x_1, y_1), (x_2, y_2), \ldots, (x_n, y_n)\\} \end{align}$$
+$$\begin{align}   & x_n = ({1248}^n\bmod 32323) - 16161 \\\\
+  & y_n = ({8421}^n\bmod 30103) - 15051 \\\\ & P_n = \\{(x_1, y_1), (x_2, y_2), \ldots, (x_n, y_n)\\} \end{align}$$
 
 Наприклад, $$P_8 = \\{(-14913, -6630), (-10161, 5625), (5226, 11896), (8340, -10778), (15852, -5203), (-15165, 11295), (-1427, -14495), (12407, 1060)\\}$$
 
@@ -18,7 +19,8 @@ $$\begin{align} & x_n = ({1248}^n\bmod 32323) - 16161 \\\\ & y_n = ({8421}^n\bmo
 
 Наприклад:
 
-$$\begin{align} & C(8) = 20 \\\\ & C(600) = 8\\,950\\,634 \\\\ & C(40\\,000) = 2\\,666\\,610\\,948\\,988 \end{align}$$
+$$\begin{align}   & C(8) = 20 \\\\
+  & C(600) = 8\\,950\\,634 \\\\ & C(40\\,000) = 2\\,666\\,610\\,948\\,988 \end{align}$$
 
 Знайдіть $C(2\\,000\\,000)$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-463-a-weird-recurrence-relation.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-463-a-weird-recurrence-relation.md
index c959c70c6a..17424a73a0 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-463-a-weird-recurrence-relation.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-463-a-weird-recurrence-relation.md
@@ -10,7 +10,9 @@ dashedName: problem-463-a-weird-recurrence-relation
 
 Функція $f$ для всіх цілих додатних чисел визначається таким чином:
 
-$$\begin{align} & f(1) = 1 \\\\ & f(3) = 3 \\\\ & f(2n) = f(n) \\\\ & f(4n + 1) = 2f(2n + 1) - f(n) \\\\ & f(4n + 3) = 3f(2n + 1) - 2f(n) \end{align}$$
+$$\begin{align}   & f(1) = 1 \\\\
+  & f(3) = 3 \\\\   & f(2n) = f(n) \\\\
+  & f(4n + 1) = 2f(2n + 1) - f(n) \\\\ & f(4n + 3) = 3f(2n + 1) - 2f(n) \end{align}$$
 
 Функція $S(n)$ визначається як $\sum_{i=1}^{n} f(i)$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-466-distinct-terms-in-a-multiplication-table.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-466-distinct-terms-in-a-multiplication-table.md
index 82f588989d..3bff5e692f 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-466-distinct-terms-in-a-multiplication-table.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-466-distinct-terms-in-a-multiplication-table.md
@@ -12,13 +12,17 @@ dashedName: problem-466-distinct-terms-in-a-multiplication-table
 
 Наприклад, таблиця множення 3×4 має такий вигляд:
 
-$$\begin{array}{c} ×          & \mathbf{1} & \mathbf{2} & \mathbf{3} & \mathbf{4}  \\\\ \mathbf{1} & 1          & 2          & 3          & 4  \\\\ \mathbf{2} & 2          & 4          & 6          & 8  \\\\ \mathbf{3} & 3          & 6          & 9          & 12 \end{array}$$
+$$\begin{array}{c}   ×          & \mathbf{1} & \mathbf{2} & \mathbf{3} & \mathbf{4}  \\\\
+  \mathbf{1} & 1          & 2          & 3          & 4  \\\\   \mathbf{2} & 2          & 4          & 6          & 8  \\\\
+  \mathbf{3} & 3          & 6          & 9          & 12 \end{array}$$
 
 Тут є 8 різних елементів {1, 2, 3, 4, 6, 8, 9, 12}, тому $P(3, 4) = 8$.
 
 Дано, що:
 
-$$\begin{align} & P(64, 64) = 1\\,263, \\\\ & P(12, 345) = 1\\,998, \text{ and} \\\\ & P(32, {10}^{15}) = 13\\,826\\,382\\,602\\,124\\,302. \\\\ \end{align}$$
+$$\begin{align}   & P(64, 64) = 1\\,263, \\\\
+  & P(12, 345) = 1\\,998, \text{ and} \\\\   & P(32, {10}^{15}) = 13\\,826\\,382\\,602\\,124\\,302. \\\\
+\end{align}$$
 
 Знайдіть $P(64, {10}^{16})$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-467-superinteger.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-467-superinteger.md
index 5cd91d5378..dc811d1cdd 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-467-superinteger.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-467-superinteger.md
@@ -14,15 +14,18 @@ dashedName: problem-467-superinteger
 
 Нехай $p(n)$ буде $n$-им простим числом, а $c(n)$ буде $n$-им складеним числом. Наприклад, $p(1) = 2$, $p(10) = 29$, $c(1) = 4$, а $c(10) = 18$.
 
-$$\begin{align} & \\{p(i) : i ≥ 1\\} = \\{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, \ldots \\} \\\\ & \\{c(i) : i ≥ 1\\} = \\{4, 6, 8, 9, 10, 12, 14, 15, 16, 18, \ldots \\} \end{align}$$
+$$\begin{align}   & \\{p(i) : i ≥ 1\\} = \\{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, \ldots \\} \\\\
+  & \\{c(i) : i ≥ 1\\} = \\{4, 6, 8, 9, 10, 12, 14, 15, 16, 18, \ldots \\} \end{align}$$
 
 Нехай $P^D$ - це послідовність цифрових коренів $\\{p(i)\\}$ ($C^D$ визначається так само, як і для $\\{c(i)\\}$):
 
-$$\begin{align} & P^D = \\{2, 3, 5, 7, 2, 4, 8, 1, 5, 2, \ldots \\} \\\\ & C^D = \\{4, 6, 8, 9, 1, 3, 5, 6, 7, 9, \ldots \\} \end{align}$$
+$$\begin{align}   & P^D = \\{2, 3, 5, 7, 2, 4, 8, 1, 5, 2, \ldots \\} \\\\
+  & C^D = \\{4, 6, 8, 9, 1, 3, 5, 6, 7, 9, \ldots \\} \end{align}$$
 
 Нехай $P_n$ - це ціле число, сформоване через об'єднання перших $n$ елементів $P^D$ ($C_n$ визначається так само, як і для $C^D$).
 
-$$\begin{align} & P_{10} = 2\\,357\\,248\\,152 \\\\ & C_{10} = 4\\,689\\,135\\,679 \end{align}$$
+$$\begin{align}   & P_{10} = 2\\,357\\,248\\,152 \\\\
+  & C_{10} = 4\\,689\\,135\\,679 \end{align}$$
 
 Нехай $f(n)$ буде найменшим позитивним цілим числом, яке є звичайним суперцілим числом $P_n$ і $C_n$. Наприклад, $f(10) = 2\\,357\\,246\\,891\\,352\\,679$, and $f(100)\bmod 1\\,000\\,000\\,007 = 771\\,661\\,825$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-468-smooth-divisors-of-binomial-coefficients.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-468-smooth-divisors-of-binomial-coefficients.md
index da7a014c48..091fd241fb 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-468-smooth-divisors-of-binomial-coefficients.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-468-smooth-divisors-of-binomial-coefficients.md
@@ -14,13 +14,15 @@ dashedName: problem-468-smooth-divisors-of-binomial-coefficients
 
 Приклади:
 
-$$\begin{align} & S_1(10) = 1 \\\\ & S_4(2\\,100) = 12 \\\\ & S_{17}(2\\,496\\,144) = 5\\,712 \end{align}$$
+$$\begin{align}   & S_1(10) = 1 \\\\
+  & S_4(2\\,100) = 12 \\\\ & S_{17}(2\\,496\\,144) = 5\\,712 \end{align}$$
 
 Визначте $F(n) = \displaystyle\sum_{B = 1}^n \sum_{r = 0}^n S_B(\displaystyle\binom{n}{r})$. Тут $\displaystyle\binom{n}{r}$ позначає біноміальний коефіцієнт.
 
 Приклади:
 
-$$\begin{align} & F(11) = 3132 \\\\ & F(1\\,111)\bmod 1\\,000\\,000\\,993 = 706\\,036\\,312 \\\\ & F(111\\,111)\bmod 1\\,000\\,000\\,993 = 22\\,156\\,169 \end{align}$$
+$$\begin{align}   & F(11) = 3132 \\\\
+  & F(1\\,111)\bmod 1\\,000\\,000\\,993 = 706\\,036\\,312 \\\\ & F(111\\,111)\bmod 1\\,000\\,000\\,993 = 22\\,156\\,169 \end{align}$$
 
 Знайдіть $F(11\\,111\\,111)\bmod 1\\,000\\,000\\,993$.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-480-the-last-question.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-480-the-last-question.md
index 03b185c050..c60de40ca7 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-480-the-last-question.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-480-the-last-question.md
@@ -16,7 +16,21 @@ $$\mathbf{\text{thereisasyetinsufficientdataforameaningfulanswer}}$$
 
 Список буде включати:
 
-$$\begin{align} & 1: \text{a} \\\\ & 2: \text{aa} \\\\ & 3: \text{aaa} \\\\ & 4: \text{aaaa} \\\\ & 5: \text{aaaaa} \\\\ & 6: \text{aaaaaa} \\\\ & 7: \text{aaaaaac} \\\\ & 8: \text{aaaaaacd} \\\\ & 9: \text{aaaaaacde} \\\\ & 10: \text{aaaaaacdee} \\\\ & 11: \text{aaaaaacdeee} \\\\ & 12: \text{aaaaaacdeeee} \\\\ & 13: \text{aaaaaacdeeeee} \\\\ & 14: \text{aaaaaacdeeeeee} \\\\ & 15: \text{aaaaaacdeeeeeef} \\\\ & 16: \text{aaaaaacdeeeeeeg} \\\\ & 17: \text{aaaaaacdeeeeeeh} \\\\ & \ldots \\\\ & 28: \text{aaaaaacdeeeeeey} \\\\ & 29: \text{aaaaaacdeeeeef} \\\\ & 30: \text{aaaaaacdeeeeefe} \\\\ & \ldots \\\\ & 115246685191495242: \text{euleoywuttttsss} \\\\ & 115246685191495243: \text{euler} \\\\ & 115246685191495244: \text{eulera} \\\\ & ... \\\\ & 525069350231428029: \text{ywuuttttssssrrr} \\\\ \end{align}$$
+$$\begin{align}   & 1: \text{a} \\\\
+  & 2: \text{aa} \\\\   & 3: \text{aaa} \\\\
+  & 4: \text{aaaa} \\\\   & 5: \text{aaaaa} \\\\
+  & 6: \text{aaaaaa} \\\\   & 7: \text{aaaaaac} \\\\
+  & 8: \text{aaaaaacd} \\\\   & 9: \text{aaaaaacde} \\\\
+  & 10: \text{aaaaaacdee} \\\\   & 11: \text{aaaaaacdeee} \\\\
+  & 12: \text{aaaaaacdeeee} \\\\   & 13: \text{aaaaaacdeeeee} \\\\
+  & 14: \text{aaaaaacdeeeeee} \\\\   & 15: \text{aaaaaacdeeeeeef} \\\\
+  & 16: \text{aaaaaacdeeeeeeg} \\\\   & 17: \text{aaaaaacdeeeeeeh} \\\\
+  & \ldots \\\\   & 28: \text{aaaaaacdeeeeeey} \\\\
+  & 29: \text{aaaaaacdeeeeef} \\\\   & 30: \text{aaaaaacdeeeeefe} \\\\
+  & \ldots \\\\   & 115246685191495242: \text{euleoywuttttsss} \\\\
+  & 115246685191495243: \text{euler} \\\\   & 115246685191495244: \text{eulera} \\\\
+  & ... \\\\   & 525069350231428029: \text{ywuuttttssssrrr} \\\\
+\end{align}$$
 
 Визначте $P(w)$ як позицію слова $w$.
 
@@ -26,7 +40,9 @@ $$\begin{align} & 1: \text{a} \\\\ & 2: \text{aa} \\\\ & 3: \text{aaa} \\\\ & 4:
 
 Приклади:
 
-$$\begin{align} & W(10) = \text{ aaaaaacdee} \\\\ & P(\text{aaaaaacdee}) = 10 \\\\ & W(115246685191495243) = \text{ euler} \\\\ & P(\text{euler}) = 115246685191495243 \\\\ \end{align}$$
+$$\begin{align}   & W(10) = \text{ aaaaaacdee} \\\\
+  & P(\text{aaaaaacdee}) = 10 \\\\   & W(115246685191495243) = \text{ euler} \\\\
+  & P(\text{euler}) = 115246685191495243 \\\\ \end{align}$$
 
 Знайдіть $$W(P(\text{legionary}) + P(\text{calorimeters}) - P(\text{annihilate}) + P(\text{orchestrated}) - P(\text{fluttering})).$$
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-74-digit-factorial-chains.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-74-digit-factorial-chains.md
index a5dd044de9..1b781835d2 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-74-digit-factorial-chains.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-74-digit-factorial-chains.md
@@ -14,11 +14,15 @@ $$1! + 4! + 5! = 1 + 24 + 120 = 145$$
 
 Можливо, менш відомим є 169, в якому він продукує найдовший ланцюг чисел, що посилається на 169; виявляється, що існує лише три такі цикли:
 
-$$\початок{align} &169 → 363601 → 1454 → 169\\\\ &871 → 45361 → 871\\\\ &872 → 45362 → 872\\\\ \кінець{align}$$
+$$\початок{align} &169 → 363601 → 1454 → 169\\\\
+&871 → 45361 → 871\\\\ &872 → 45362 → 872\\\\
+\кінець{align}$$
 
 Не важко довести, що КОЖНЕ початкове число врешті застрягне в циклі. Наприклад,
 
-$$\початок{align} &69 → 363600 → 1454 → 169 → 363601\\ (→ 1454)\\\\ &78 → 45360 → 871 → 45361\\ (→ 871)\\\\ &540 → 145\\ (→ 145)\\\\ \кінець{align}$$
+$$\початок{align} &69 → 363600 → 1454 → 169 → 363601\\ (→ 1454)\\\\
+&78 → 45360 → 871 → 45361\\ (→ 871)\\\\ &540 → 145\\ (→ 145)\\\\
+\кінець{align}$$
 
 Починаючи з 69 продукується ланцюжок з 5 неповторних значень, але найдовший неповторний ланцюжок з початковим числом нижче одного мільйона - це шістдесят значень.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-81-path-sum-two-ways.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-81-path-sum-two-ways.md
index ab48564c2f..18a29d1fd7 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-81-path-sum-two-ways.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-81-path-sum-two-ways.md
@@ -10,7 +10,9 @@ dashedName: problem-81-path-sum-two-ways
 
 У наведеній нижче матриці 5 на 5 мінімальна сума шляху від верхнього лівого кута до нижнього правого, ** рухаючись тільки вправо і вниз **, виділена жирним червоним шрифтом і дорівнює `2427`.
 
-  $$\початок{pmatrix} \color{red}{131} & 673 & 234 & 103 & 18\\\\ \color{red}{201} & \color{red}{96} & \color{red}{342} & 965 & 150\\\\ 630 & 803 & \color{red}{746} & \color{red}{422} & 111\\\\ 537 & 699 & 497 & \color{red}{121} & 956\\\\ 805 & 732 & 524 & \color{red}{37} & \color{red}{331} \кінець{pmatrix}$$
+  $$\початок{pmatrix}   \color{red}{131} & 673 & 234 & 103 & 18\\\\
+  \color{red}{201} & \color{red}{96} & \color{red}{342} & 965 & 150\\\\   630 & 803 & \color{red}{746} & \color{red}{422} & 111\\\\
+  537 & 699 & 497 & \color{red}{121} & 956\\\\ 805 & 732 & 524 & \color{red}{37} & \color{red}{331} \кінець{pmatrix}$$
 
 Знайдіть мінімальну суму шляху з лівого верхнього кута до нижнього правого, рухаючись лише праворуч і вниз по осі `matrix`, 2D масив, що представляє матрицю. Максимальний розмір матриці, що використовується в тестах, дорівнюватиме 80 на 80.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-82-path-sum-three-ways.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-82-path-sum-three-ways.md
index b7f829e17e..161ef5b3ba 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-82-path-sum-three-ways.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-82-path-sum-three-ways.md
@@ -12,7 +12,9 @@ dashedName: problem-82-path-sum-three-ways
 
 Мінімальна сума шляху в наведеній нижче матриці 5 на 5, починаючи з будь-якої клітинки в лівому стовпці, та закінчуючись в будь-якій клітинці у правому стовпці, та рухаючись лише вгору, вниз а праворуч, виділена червоним і жирним шрифтом; сума дорівнює `994`.
 
-  $$\початок{pmatrix} 131 & 673 & \color{red}{234} & \color{red}{103} & \color{red}{18}\\\\ \color{red}{201} & \color{red}{96} & \color{red}{342} & 965 & 150\\\\ 630 & 803 & 746 & 422 & 111\\\\ 537 & 699 & 497 & 121 & 956\\\\ 805 & 732 & 524 & 37 & 331 \кінець{pmatrix}$$
+  $$\початок{pmatrix}   131 & 673 & \color{red}{234} & \color{red}{103} & \color{red}{18}\\\\
+  \color{red}{201} & \color{red}{96} & \color{red}{342} & 965 & 150\\\\   630 & 803 & 746 & 422 & 111\\\\
+  537 & 699 & 497 & 121 & 956\\\\ 805 & 732 & 524 & 37 & 331 \кінець{pmatrix}$$
 
 Знайдіть мінімальну суму шляху з лівого стовпця в правий стовпець у `matrix`, 2D масив представляє матрицю. Максимальний розмір матриці, що використовується в тестах, дорівнюватиме 80 на 80.
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-83-path-sum-four-ways.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-83-path-sum-four-ways.md
index 4adf6b7ad3..1939c9a5f7 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-83-path-sum-four-ways.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-83-path-sum-four-ways.md
@@ -12,7 +12,9 @@ dashedName: problem-83-path-sum-four-ways
 
 У нижче наведеній матриці 5 на 5 мінімальна сума шляху з лівого верхнього кута до нижнього правого, рухаючись ліворуч, праворуч, вгору і вниз, виділена жирним червоним шрифтом і дорівнює `2297`.
 
-  $$\початок{pmatrix} \color{red}{131} & 673 & \color{red}{234} & \color{red}{103} & \color{red}{18}\\\\ \color{red}{201} & \color{red}{96} & \color{red}{342} & 965 & \color{red}{150}\\\\ 630 & 803 & 746 & \color{red}{422} & \color{red}{111}\\\\ 537 & 699 & 497 & \color{red}{121} & 956\\\\ 805 & 732 & 524 & \color{red}{37} & \color{red}{331} \кінець{pmatrix}$$
+  $$\початок{pmatrix}   \color{red}{131} & 673 & \color{red}{234} & \color{red}{103} & \color{red}{18}\\\\
+  \color{red}{201} & \color{red}{96} & \color{red}{342} & 965 & \color{red}{150}\\\\   630 & 803 & 746 & \color{red}{422} & \color{red}{111}\\\\
+  537 & 699 & 497 & \color{red}{121} & 956\\\\ 805 & 732 & 524 & \color{red}{37} & \color{red}{331} \кінець{pmatrix}$$
 
 Знайдіть мінімальну суму шляху з лівого верхнього кута до нижнього правого, рухаючись ліворуч, праворуч, вгору та вниз у `matrix<code>, 2D масив представляє матрицю. Максимальний розмір матриці, що використовується в тестах, дорівнюватиме 80 на 80.</p>
 
diff --git a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-92-square-digit-chains.md b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-92-square-digit-chains.md
index b5b2266552..2184b2c15e 100644
--- a/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-92-square-digit-chains.md
+++ b/curriculum/challenges/ukrainian/10-coding-interview-prep/project-euler/problem-92-square-digit-chains.md
@@ -12,7 +12,8 @@ dashedName: problem-92-square-digit-chains
 
 Наприклад,
 
-$$\begin{align} & 44 → 32 → 13 → 10 → \boldsymbol{1} → \boldsymbol{1}\\\\ & 85 → \boldsymbol{89} → 145 → 42 → 20 → 4 → 16 → 37 → 58 → \boldsymbol{89}\\\\ \end{align}$$
+$$\begin{align}   & 44 → 32 → 13 → 10 → \boldsymbol{1} → \boldsymbol{1}\\\\
+  & 85 → \boldsymbol{89} → 145 → 42 → 20 → 4 → 16 → 37 → 58 → \boldsymbol{89}\\\\ \end{align}$$
 
 Таким чином, будь-яка послідовність, що призводить до отримання 1 або 89, замкнеться в нескінченний цикл. Найдивовижніше, що БУДЬ-ЯКЕ початкове число рано чи пізно дасть 1 або 89.