Math Help - summation Induction

1. summation Induction

I want to solve this problem using Induction

$\sum _{i=0}^{x - n} {(x - (i + 1)) \choose n } = {x \choose n + 1}$

How can I prove it .......................

2. Re: summation Induction

$\sum _{i=0}^{x - n} {(x - (i + 1)) \choose n } = {x \choose n + 1}$