Work out the first three terms in the binomial expansion of 1(k+3x)2\displaystyle \frac{1}{(k+3x)^2}(k+3x)21, where k≠0k\ne0k=0.
Write down the range of values of x x\,x for which the expansion is valid.
408 exam-style questions on Edexcel A Level Maths Binomial Expansion, covering 4.1 Expanding (1 + x)^n, 4.2 Expanding (a + bx)^n, and 4.3 Using Partial Fractions. Each one has a worked solution and a mark scheme showing where the marks go.