(a)[1]
Expand the expression $\left(1 - \frac{1}{2x}\right)^2$.
(b)[2]
Find the first four terms of the expansion of $(1 + 2x)^6$, in ascending powers of $x$.
(c)[2]
Hence find the coefficient of $x$ when $\left(1 - \frac{1}{2x}\right)^2 (1 + 2x)^6$ is expanded.