Expand f(x) = (x+x^2)/((1-x)^3) as a power series and use it to find the sum of series (SUM from n=1 to infinity) (n^2)/(2^n)

Question

PLEASE HELP.

Answer 1

Taylor series is as follows:

f(x)=f(a)+f'(a)(x-a)/1!+f''(a)(x-a)^2/2!+f'''(a)(x-a)^3/3!+...