Work out the first three terms in the binomial expansion of 1(5+2x)2\displaystyle \frac{1}{(5+2x)^2}(5+2x)21
Write down the range of values of x x\,x for which the expansion is valid.
43 exam-style questions on WJEC A Level Maths 3.4.1 Sequences and Series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.