Question

simplifique as expressões
por favor​

Answer 1

Explicação passo-a-passo:

a)

$\frac{n!}{(n-1)!} =\frac{n.(n-1)!}{(n-1)!}\\\\\frac{n!}{(n-1)!}=n$

b)

$\frac{n!-(n+1)!}{n!}=\frac{n!-[(n+1).n!]}{n!}\\\\\frac{n!-(n+1)!}{n!}=\frac{n!(1-(n+1)}{n!} \\\\\frac{n!-(n+1)!}{n!}=1-n-1\\\\\frac{n!-(n+1)!}{n!}=-n$