Expand (1−2x)−3(1-2x)^{-3}(1−2x)−3 in ascending powers of x x\,x up to and including x3x^3x3
Write down the range of values of x x\,x for which the expansion is valid.
Use your expansion to find the expansion of 1+x(1−2x)3\displaystyle \frac{1+x}{(1-2x)^3}(1−2x)31+x up to and including x3x^3x3