Question: How do you prove∑s(n+sk+l)(ks)(ls)=(nk)(nl)
I'm just not sure where to begin. I tried writing both sides as the coefficient of xn of the expansion of a binomial. But obviously, that doesn't fit the right-hand side because it's the product of two binomials.
I'm guessing that we'll need the multinomial theorem. Is that correct? Do you have any other ideas?
No comments:
Post a Comment