help binomial expansion

[primal cloak]

u did the first part of part b right as in u need to binomially expand (1-1/2x)^2

andthen u wanna times the answer u got in part a to the answer u got in part b

and then once its fully expanded simplify it and find the coefifcient of x^3

u were on the right track

just carry on with it

[vivid grotto]

is there not an easier way to do it

because its all fractions

and there are so many terms to times together

actually i guess its not that bad if i just use my calculator for most of it