0580/31 Oct/Nov 2025, Question 21: The Equation y = mx + c
Cambridge IGCSE Mathematics 0580 · Paper 31 (Core) · Calculator · 3 marks
اقرأ هذا الحل مشروحاً بالعربي ←
The question, in short
Using the straight line L drawn on the grid, find its equation and give it in the form y = mx + c.
Summarised in our own words. Use the official paper for the exact wording and the diagram.
Solution · 3 marks
- 1L crosses the y-axis at (0, 5), so c = 5
- 2From (0, 5) to (4, 17): rise = 12, run = 4
- 3Gradient m = 12 ÷ 4 = 3
- 4y = 3x + 5
Answer3x + 5
Stuck on a step? Read the free lesson: The Equation y = mx + c
Practise more the equation y = mx + c 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 the equation y = mx + c
Also searched as: 0580/31/O/N/25 · 0580_w25_qp_31 · 0580 w25 31 · question 21.
Lemmara is an independent study tool, not affiliated with or endorsed by Cambridge International Education. The worked solutions are Lemmara’s own.