Lemmara logoLemmaraWorked solution

0580/12 Oct/Nov 2021, Question 16: Solving Linear Equations

Cambridge IGCSE Mathematics 0580 · Paper 12 (Core) · Calculator · 3 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Solve a linear equation for x, then use index laws to find the exponent y in a product of powers of 7.

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

Part (a) · 2 marks

Solve 7x + 18 = 4 to find the value of x.

  1. 17x = 4 − 18 = −14
  2. 2x = −2

Answer−2

Part (b) · 1 mark

Given 7ʸ × 7⁶ = 7¹⁸, find the value of y.

  1. 17ʸ⁺⁶ = 7¹⁸, so y + 6 = 18
  2. 2y = 12

Answer12

Stuck on a step? Read the free lesson: Solving Linear Equations

Practise more solving linear equations questions

Real 0580 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on solving linear equations

Also searched as: 0580/12/O/N/21 · 0580_w21_qp_12 · 0580 w21 12 · question 16.
Lemmara is an independent study tool, not affiliated with or endorsed by Cambridge International Education. The worked solutions are Lemmara’s own.