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4MA1/2HR Jan 2019, Question 10: Solving Linear Equations

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2HR (Higher) · Calculator · 7 marks

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The question, in short

Simplify a power of a product, solve an equation involving two algebraic fractions equal to 4, and rearrange a formula containing a square root to make f the subject.

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

Part (a) · 2 marks

Simplify fully the expression (16x⁸y⁶)^(1/2).

  1. 1A power of ½ is a square root, so take the square root of each part
  2. 2√16 = 4, √(x⁸) = x⁴ and √(y⁶) = y³
  3. 3So the answer is 4x⁴y³

Answer4x⁴y³

Part (b) · 3 marks

Solve (8 − 2x)/3 − (2x − 3)/2 = 4, showing clear algebraic working.

  1. 1Multiply every term by 6, the common denominator: 2(8 − 2x) − 3(2x − 3) = 24
  2. 2Expand: 16 − 4x − 6x + 9 = 24
  3. 3Collect terms: 25 − 10x = 24, so 10x = 1
  4. 4x = 0.1

Answer0.1

Part (c) · 2 marks

Make f the subject of the formula m = √((1/3)ef).

  1. 1Square both sides to clear the square root: m² = ef/3
  2. 2Multiply both sides by 3: 3m² = ef
  3. 3Divide by e: f = 3m²/e

Answer3m²/e

Stuck on a step? Read the free lesson: Solving Linear Equations

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