Verify that x=4−2aa−1\displaystyle x = \frac{4 - 2a}{a - 1}x=a−14−2a satisfies the formula a=x+4x+2\displaystyle a = \frac{x+4}{x+2}a=x+2x+4
215 exam-style questions on OCR GCSE Maths Rearranging Harder Formulae. Each one has a worked solution and a mark scheme showing where the marks go.