Question

dada a expressão (imagem)
help me ​

Answer 1

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

$\frac{1}{(n+3)(n+2)(n+1)n(n-1)} *(n+2)(n+1)n=$

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

$\frac{1}{(n+3)(n-1)}$