Question

Simplifique a) (n+3)!×(n+1)!/n!×(n+4) b) (n+1)! × -2n!/(n+1)!×(n-1)!

Answer 1

$a) \frac{(n+3)!.(n+1)!}{n!.(n+4)!} = \frac{(n+3)!.(n+1).n!}{n!.(n+4).(n+3)!} = \frac{(n+1)}{(n+4)} \\ \\ b) \frac{(n+1)!.-2n!}{(n+1)!.(n-1)!} = \frac{(n+1)!.-2n.(n-1)!}{(n+1)!.(n-1)!} = -2.n$

Espero ter ajudado.