Find the first four terms, in ascending powers of xxx, of the binomial expansion of
(3+16x)9\left(3 + \frac{1}{6}x\right)^9(3+61x)9Give each coefficient as a simplified fraction or an integer where possible.
99 exam-style questions on CCEA A Level Maths 1.3.1 Sequences and series. Each one has a worked solution and a mark scheme showing where the marks go.