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4MA1/1FR Jan 2020, Question 16: Rearranging Formulas

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1FR (Foundation) · Calculator · 8 marks

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The question, in short

Four short algebra tasks: rearrange a formula, factorise, expand two brackets, and simplify an index expression.

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

Part (a) · 2 marks

Rearrange d = g + 2ac to make a the subject.

  1. 1d = g + 2ac
  2. 2d − g = 2ac
  3. 3(d − g)/(2c) = a

Answer(d − g)/(2c)

Part (b) · 2 marks

Factorise 9ef − 12f completely.

  1. 1The highest common factor of 9ef and 12f is 3f.
  2. 29ef ÷ 3f = 3e and 12f ÷ 3f = 4
  3. 39ef − 12f = 3f(3e − 4)

Answer3f(3e − 4)

Part (c) · 2 marks

Expand and simplify (x + 2)(x − 5).

  1. 1x × x = x² and x × (−5) = −5x
  2. 22 × x = 2x and 2 × (−5) = −10
  3. 3x² − 5x + 2x − 10 = x² − 3x − 10

Answerx² − 3x − 10

Part (d) · 2 marks

Simplify (n⁴ × n⁷) ÷ n⁵ fully.

  1. 1Multiply: add the powers, n⁴ × n⁷ = n¹¹
  2. 2Divide: subtract the powers, n¹¹ ÷ n⁵ = n⁶

Answern⁶

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