let m,n be positive integer. Prove the identity:(adsbygoogle = window.adsbygoogle || []).push({});

sum (i from 0 to k): { C(m, i) * C(n, k - i) } = C(m + n, k)

Hint: Consider the polynomial equation:

sum (k from 0 to m+n) {C(m + n, k) *z^k } = (1 + z)^(m+n) = ((1+z)^m) * ((1+z)^n)

I tried long time, still have no idea.

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# Homework Help: Applied Algebra (Prove the identity)?

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