Question

Simplifique as expressões. a) 20! sobre 18!, b) n! Sobre (n-2), c) (n+1)! Sobre (n+2)!

Answer 1

Resposta:

$a)\frac{20!}{18!}=\frac{20.19.18!}{18!}=20.19=380\\\\b)\frac{n!}{n-2}=\frac{n(n-1)(n-2)(n-3)!}{n-2}=n(n-1)(n-3)!\\\\c)\frac{(n+1)!}{(n+2)!} =\frac{(n+1)!}{(n+2)(n+1)!} =\frac{1}{n+2}$