Question

(n+2)! . (n-1)! / (n+3)! n!

Answer 1

(n+3)!=(n+3)(n+2)!

simplificando (n+2)!

(n-1)!/(n+3)n!

n!=n(n-1)!

simplificando (n-1)!

1/n(n+3)

[1/n²+3n] //.