Lemmara logoLemmaraWorked solution

0580/12 Feb/Mar 2021, Question 18: Index Laws with Letters

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

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Simplify two index expressions and solve an equation with 3 to the power p equal to 1/81 to find p.

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

Part (ai) · 1 mark

Simplify x¹² ÷ x³, giving the result as a single power of x.

  1. 1x¹² ÷ x³ = x¹²⁻³ = x⁹

Answerx⁹

Part (aii) · 1 mark

Simplify (y²)⁵, writing the answer as a single power of y.

  1. 1(y²)⁵ = y^(2 × 5) = y¹⁰

Answery¹⁰

Part (b) · 1 mark

Given 3ᵖ = 1/81, find the value of p.

  1. 181 = 3⁴ so 1/81 = 3⁻⁴
  2. 2p = −4

Answer−4

Stuck on a step? Read the free lesson: Index Laws with Letters

Practise more index laws with letters 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 index laws with letters

Also searched as: 0580/12/F/M/21 · 0580_m21_qp_12 · 0580 m21 12 · question 18.
Lemmara is an independent study tool, not affiliated with or endorsed by Cambridge International Education. The worked solutions are Lemmara’s own.