Question

Simplifique as expressões
(N-4)!/ (n-3)!

(2n)! / (2n-2)!

Answer 1

$\frac{(n-4)!}{(n-3)!}=\frac{(n-4)!}{(n-3)(n-4)!}= \frac{1}{(n-3)} \\ \\ \\ \frac{(2n)!}{(2n-2)!}=\frac{(2n)(2n-1)(2n-2)!}{(2n-2)!}=2n(2n-1)$