Question

n! supra (n-2)!
permutari!
ajutor

Answer 1

n!=(n-2)!(n-1)*n
n!/(n-2)=(n-2)!(n-1)*n(n-2)!=(n-1)*n

Answer 2

$\dfrac{n!}{(n-2)!} = \\ \\ = \dfrac{(n-2)!\cdot(n-1)\cdot n}{(n-2)!} = \\ \\ = (n-1)\cdot n$