0580/23 Oct/Nov 2023, Question 20: Expand and Simplify
Cambridge IGCSE Mathematics 0580 · Paper 23 (Extended) · Calculator · 3 marks
اقرأ هذا الحل مشروحاً بالعربي ←
The question, in short
Expand (x + a)(x + 2)(2x + 3) and compare with 2x³ + bx² + cx − 18 to find the values of a, b and c.
Summarised in our own words. Use the official paper for the exact wording and any diagrams.
Solution · 3 marks
- 1Constant term: a × 2 × 3 = −18, so a = −3
- 2(x + 2)(2x + 3) = 2x² + 7x + 6
- 3(x − 3)(2x² + 7x + 6) = 2x³ + 7x² + 6x − 6x² − 21x − 18 = 2x³ + x² − 15x − 18
- 4a = −3, b = 1, c = −15
Answera = −3, b = 1, c = −15
Stuck on a step? Read the free lesson: Expand and Simplify
Practise more expand and simplify questions
Real 0580 past-paper questions, marked on your working like the exam, with a worked solution for every part.
Practise free on LemmaraMore past-paper questions on expand and simplify
Also searched as: 0580/23/O/N/23 · 0580_w23_qp_23 · 0580 w23 23 · question 20.
Lemmara is an independent study tool, not affiliated with or endorsed by Cambridge International Education. The worked solutions are Lemmara’s own.