0
$\begingroup$

I would like to prove the following statement to be true. $$ \sum_{k = 0}^{m} \binom{m}{k}\binom{n+k}{m} = \sum_{k = 0}^{m}\binom{n}{k}\binom{m}{k}2^{k} $$

$\endgroup$

marked as duplicate by Namaste, Jendrik Stelzner, N. F. Taussig combinatorics Aug 26 '18 at 11:16

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ First, I would try to express the combinatorial expressions as fractions. $\endgroup$ – David Aug 26 '18 at 11:08