Can someone explain to me how i would go about this problem?
Here's how I thought about it. After all terms with identical sets of exponents are added, each term looks like this: $ x_{1}^{?}*x_{2}^{?}*...*x_{m}^{?} $. All the exponents have to add up to n, and there are m x's on which to place exponents. So, the question is simply a case of partitioning n identical items into m distinguishable groups. How many different terms are there? I think the answer is (n+m-1) choose (m-1), but I don't know how to write it in Latex. =P Anyway, I hope this helps. -Zoe
