fix(curriculum): clean-up Project Euler 441-460 (#43068)

* fix: clean-up Project Euler 441-460

* fix: corrections from review

Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>

Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>

curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-446-retractions-b.md

@@ -8,20 +8,26 @@ dashedName: problem-446-retractions-b
 
 # --description--
 
-For every integer n>1, the family of functions fn,a,b is defined
+For every integer $n > 1$, the family of functions $f_{n, a, b}$ is defined by:
 
-by fn,a,b(x)≡ax+b mod n for a,b,x integer and 0
+$f_{n, a, b}(x) ≡ ax + b\bmod n$ for $a, b, x$ integer and $0 \lt a \lt n$, $0 \le b \lt n$, $0 \le x \lt n$.
 
-F(N)=∑R(n4+4) for 1≤n≤N. F(1024)=77532377300600.
+We will call $f_{n, a, b}$ a retraction if $f_{n, a, b}(f_{n, a, b}(x)) \equiv f_{n, a, b}(x)\bmod n$ for every $0 \le x \lt n$.
 
-Find F(107) (mod 1 000 000 007)
+Let $R(n)$ be the number of retractions for $n$.
+
+$F(N) = \displaystyle\sum_{n = 1}^N R(n^4 + 4)$.
+
+$F(1024) = 77\\,532\\,377\\,300\\,600$.
+
+Find $F({10}^7)$. Give your answer modulo $1\\,000\\,000\\,007$.
 
 # --hints--
 
-`euler446()` should return 907803852.
+`retractionsB()` should return `907803852`.
 
 ```js
-assert.strictEqual(euler446(), 907803852);
+assert.strictEqual(retractionsB(), 907803852);
 ```
 
 # --seed--
@@ -29,12 +35,12 @@ assert.strictEqual(euler446(), 907803852);
 ## --seed-contents--
 
 ```js
-function euler446() {
+function retractionsB() {
 
   return true;
 }
 
-euler446();
+retractionsB();
 ```
 
 # --solutions--