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0580/41 May/Jun 2025, Question 21: Exponential Equations

Cambridge IGCSE Mathematics 0580 · Paper 41 (Extended) · Calculator · 3 marks

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The question, in short

Solve 16^(5m)/4 = 64^(2n) for m, giving the answer as an expression involving n.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Solution · 3 marks

  1. 116^(5m) = 4^(2 × 5m) = 4^(10m), so 16^(5m)/4 = 4^(10m − 1)
  2. 264^(2n) = 4^(3 × 2n) = 4^(6n)
  3. 310m − 1 = 6n
  4. 4m = (6n + 1)/10

Answer(6n + 1)/10

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Also searched as: 0580/41/M/J/25 · 0580_s25_qp_41 · 0580 s25 41 · question 21.
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