VandermondesIdentity.md (277B)
1 # Vandermonde's Identity 2 3 Ch 6.4 4 5 **Definition:** Vandermonde's identity is an identity that describes n+m choose k as a sum of all ways to select 0 of one and k of the other 1 of one and k-1 of the other and so on. 6 7 $\binom{n+m}{k} = \sum^k_{i=0} \binom{n}{i} \binom{m}{k-i}$