I'd start by writing out the first few terms of each sum. You might see something cool happen...
Hello I need help with this question:
If f(x) is a funciton of x, defined for all nonnegative integers, simliplify the sum
Then i kind of expanded f (i-1) in wrongly by saying it's equal to f(i) - f(1).
My final answer is wrong because of this assumption.
Where should I go from here?