Respostas

2014-03-15T19:18:47-03:00
(n + 2)! = (n + 2)·(n + 1)! = n + 2
(n + 1)!          (n + 1)!
2014-03-15T19:37:01-03:00
= (n+2) x (n+1)! /(n+1)! 
=(n+2)