AngularJS Expressions (#20839)

* AngularJS Expressions

* fixed formatting and removed redundancy

guide/english/angularjs/index.md

@@ -7,6 +7,17 @@ title: AngularJS
 It reduces the repetitive use of HTML code. This repetition can be avoided by using the directives provided by AngularJS which saves 
 much time and effort.
 
+## AngularJS Expressions
+- Expressions can be written inside double braces: `{{ expression }}`
+- Expressions can also be written inside a directive: `ng-bind="expression"`
+- AngularJS will resolve the expression, and return the result exactly where the expression is written
+- Expressions are much like JavaScript expressions: They can contain literals, operators, and variables.
+
+Example:
+```js
+{{ 5 + 5 }} or {{ firstName + " " + lastName }}
+```
+
 **Install**:
 
 npm: