Question

Simplifique a fração:

(n-3)! / (n-1)!

Answer 1

$Resolu\c{c}\~ao \to \left\{\begin{array}{ccc}\frac{(n-3)!}{(n-1)!} = \frac{(n-3)!}{(n-1)*(n-2)*(n-3)!} = \frac{1}{(n-1)*(n-2)} = \frac{1}{n^2-3n+2}\end{array}\right$

Espero ter ajudado. :))

Answer 2

Queremos simplificar $\dfrac{(n-3)!}{(n-1)!}$.

Veja que, $(n-1)!=(n-1)(n-2)(n-3)!$

Logo, $\dfrac{(n-3)!}{(n-1)!}=\dfrac{(n-3)!}{(n-1)(n-2)(n-3)!}=\dfrac{1}{(n-1)(n-2)}$