Question

co simplificar (n+1)!-2n!/n!+(n-1)!

Answer 1

(n+1)(n)(n-1)! - 2(n)(n-1)! / (n)(n-1)! + (n-1)!
= (n-1)! ( n×(n+1) - 2n ) / (n-1)! ( n + 1 )

Corta os (n-1)!

= (n^2 - n) / ( n+1 )

O resultado é
$\frac{ {n}^{2} - n}{n + 1}$