Find the coefficient on x^10 in the following generating function

Question

$\ {(1 − x^{14})\over (1 − x)}$

My thought was:

$\ (1-x^{14})\over (1-x)$ $\ = (1 - x^{14}) ∑ x^n$ $\ = ∑ [x^n - x^{n+14}]$

But I'm not sure if I'm on the right path?

Answer 1

HINT: $\frac{1-x^{p+1}}{1-x}=1+x+x^2+x^3+...+x^p$ (is called the "Geometric series") for arbitrary number $p$.