Question

Sa se calculeze:
n 1
C - C , n € N
n+1 n+1

Answer 1

combinari de n+1 luate cate n = (n+1)!  /  n! 1! = n+1
---- " ------- de n+1 luate cate 1= (n+1!  / 1! (n+1-1)! = n+1
si scazandu-le obinem  rezultatul 0(zero).

Answer 2

[tex]\it C^k_n = C_n^{n-k} \\ \\ C_{n+1}^n = C_{n+1}^{n+1-n} = C_{n+1}^1=n+1[/tex]