HELP HURRYDUE SOON

Proceed as in example 3 in section 6.1 to rewrite the given expression using a single power series whose general term involves xk. ∞ n(n − 1)cnxn − 2 n = 2 − 4 ∞ ncnxn n = 1 + ∞ cnxn n = 0

What is the sum of the first 8 terms of the geometric series

Which equation can be solved to find x the measure of jk in the apex