The expansion of (12+8x)12\displaystyle (12 + 8x)^{\frac{1}{2}}(12+8x)21 in ascending powers of x x\,x up to and including x3 x^3\,x3 is
23+233x−39x2+327x3 2\sqrt{3} + \frac{2\sqrt{3}}{3}x - \frac{\sqrt{3}}{9}x^2 + \frac{\sqrt{3}}{27}x^3 23+323x−93x2+273x3Use your expansion, with x=0.1x = 0.1x=0.1, to find an approximation of the value of 5\sqrt{5}5. Give your answer to 3 decimal places.
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.