0580/31 May/Jun 2026, Question 20: Substitution
Cambridge IGCSE Mathematics 0580 · Paper 31 (Core) · Calculator · 5 marks
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The question, in short
Given P = 5x + 4y, find x when P = 18 and y = −3, then factorise 6x² + 12x.
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Part (a) · 3 marks
Substitute P = 18 and y = −3 into P = 5x + 4y and solve for the value of x.
- 118 = 5x + 4 × (−3)
- 218 = 5x − 12
- 330 = 5x
- 4x = 6
Answer6
Part (b) · 2 marks
Factorise the expression 6x² + 12x fully.
- 1HCF of 6x² and 12x is 6x
- 26x² + 12x = 6x(x + 2)
Answer6x(x + 2)
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Also searched as: 0580/31/M/J/26 · 0580_s26_qp_31 · 0580 s26 31 · question 20.
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