Make r r\,r the subject of the formula 1s=1r+1t\displaystyle \frac{1}{s} = \frac{1}{r} + \frac{1}{t}s1=r1+t1
Practise OCR GCSE Maths Rearranging Harder Formulae with exam-style questions for Foundation and Higher tier. 52 questions, matched to the OCR GCSE Maths (J560) specification and written in the written papers style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.