The expression (25−4x)12\displaystyle (25-4x)^{\frac{1}{2}}(25−4x)21 is expanded in ascending powers of xxx.
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.