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4024/12 Oct/Nov 2022, Question 22: Factorising by Grouping

Cambridge O Level Mathematics 4024 · Paper 12 (Non-calculator) · Non-calculator · 3 marks

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The question, in short

Factorise two expressions: a difference of two squares in p and q, and a four-term expression in a, b and c by grouping.

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

Part (a) · 1 mark

Factorise 9p² − q².

  1. 19p² − q² = (3p)² − q²
  2. 2= (3p + q)(3p − q)

Answer(3p + q)(3p − q)

Part (b) · 2 marks

Factorise ac − 3bc + a − 3b.

  1. 1ac − 3bc + a − 3b = c(a − 3b) + 1(a − 3b)
  2. 2= (a − 3b)(c + 1)

Answer(a − 3b)(c + 1)

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Also searched as: 4024/12/O/N/22 · 4024_w22_qp_12 · 4024 w22 12 · question 22.
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