Find the coefficient of x5 x^5\,x5 in the expansion of (1+5x)8(1 + 5x)^8(1+5x)8
Expand 1−8x \sqrt{1 - 8x}\,1−8x as far as the term x3x^3x3.
State the range of the values for which your expansion is valid.
Use your expansion to find an estimate for 891\sqrt{891}891, correct to five decimal places, and compare this with the value of 891 \sqrt{891}\,891 given by your calculator.
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.