I always seem to have problems solving questions such as (ii) below & I've seen them in pretty much every past paper. Can someone please explain to me how to solve (ii)?
(i) Find the first 3 terms in the expansion of (2 + 3x)^5 in ascending powers of x.
(ii) Hence find the value of the constant a for which there is no term in x^2 in the expansion of
(1 + ax)(2 + 3x)^2.
Thanks.