The slope of a parallel line with the equation y=1/2x+6

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 base of 1/9 to the power of 2

Precalculus question, image attached.