Question

Combinări de n+2 luate câte n+1?

Answer 1

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

Answer 2

$\frac{(n+2)!}{(n+1)!*1!} = \frac{n+1)!(n+2)}{n+1)!} =n+2$