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4MA1/2FR Jan 2022, Question 15: Substitution

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2FR (Foundation) · Calculator · 6 marks

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The question, in short

Solve a linear equation, expand a product, evaluate T = 5m − 6n for given m and n, and rearrange k = 2g + t to make g the subject.

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

Part (a) · 1 mark

Solve 5c = 15 for c.

  1. 115 / 5 = 3

Answer3

Part (b) · 1 mark

Expand x(8 − x).

  1. 1x × 8 = 8x
  2. 2x × (−x) = −x²
  3. 38x − x²

Answer8x − x²

Part (c) · 2 marks

Find T when m = 4.2 and n = −2.5 in T = 5m − 6n.

  1. 1T = 5 × 4.2 − 6 × (−2.5)
  2. 25 × 4.2 = 21
  3. 3−6 × (−2.5) = +15
  4. 4T = 21 + 15 = 36

Answer36

Part (d) · 2 marks

Rearrange k = 2g + t to make g the subject.

  1. 1k − t = 2g
  2. 2(k − t) / 2 = g

Answer(k − t)/2

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