simplify the given expressions, then make a list of the like terms that appear in your final answer

4^n+4n-4n^2 + (2^n-2n)

This is really just like the other one - but simpler. You don't even need the brackets, assuming the question is written correctly:

4^n + 4n -4n^2 + 2^n - 2n

(4n - 2n = 2n, sp)

4^n + 2^n - 4n^2 + 2n