there are many ways to think of that problem. My suggestion to start with the inside term is based on future problems being more difficult.

You will be taking summations and finding algebraic expressions for them based on identities.

you will want to simplify the inside terms, more often than otherwise.


----another way to look at this problem: take the 4 all the way outside to the left and replace it with 1.

what is the summation of 1 ?


this may help explain what nate is suggesting and what you were trying to explain.