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4024/22 Oct/Nov 2023, Question 4: Constructing Equations

Cambridge O Level Mathematics 4024 · Paper 22 (Calculator) · Calculator · 8 marks

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The question, in short

Solve a linear equation, form and solve an equation in n for fruit masses totalling 450 grams, and solve a quadratic by factorisation.

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

Part (a) · 2 marks

Solve 5x + 6 = 3x for x.

  1. 15x − 3x = −6
  2. 22x = −6
  3. 3x = −3

Answer−3

Part (b) · 3 marks

With plum n grams, apple twice plum, banana 50 g more than apple, total 450 g: form an equation in n and solve for the plum's mass.

  1. 1Apple = 2n, banana = 2n + 50
  2. 2n + 2n + 2n + 50 = 450
  3. 35n = 400
  4. 4n = 80 g

Answer80

Part (c) · 3 marks

Solve x² − 4x − 21 = 0 by factorisation.

  1. 1Two numbers with product −21 and sum −4: +3 and −7
  2. 2(x + 3)(x − 7) = 0
  3. 3x = −3 or x = 7

Answerx = −3 or x = 7

Stuck on a step? Read the free lesson: Constructing Equations

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Also searched as: 4024/22/O/N/23 · 4024_w23_qp_22 · 4024 w23 22 · question 4.
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