GCSE · Formulae & rearranging

Changing the subject when it appears twiceExam-style questions

Why a subject that appears twice must be collected and FACTORISED out, how clearing a fraction first exposes both copies, and the four-step routine that untangles any of these.

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11 questions · GCSE (Higher) level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 3Level 4Level 5
  1. 1
    Make xx the subject of 5x−3=y(x+4)5x - 3 = y(x + 4) (3 marks)
    Level 3 · 3 marksTry it
  2. 2
    Make xx the subject of   ax+7=bx+c\;ax + 7 = bx + c
    Level 4 · 3 marksTry it
  3. 3
    Make nn the subject of   m=3(n−5)n\;m = \dfrac{3(n - 5)}{n}
    Level 4 · 3 marksTry it
  4. 4
    Make xx the subject of   a(x+2)=b(x−5)\;a(x + 2) = b(x - 5)
    Level 4 · 4 marksTry it
  5. 5
    Make tt the subject of   s=2t+3t\;s = \dfrac{2t + 3}{t}
    Level 4 · 3 marksTry it

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