Lemmara logoLemmaraWorked solution

4MA1/1H Jun 2018, Question 11: Expand and Simplify

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1H (Higher) · Calculator · 6 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Expand and simplify a product of three linear brackets, then solve a quadratic equation, giving answers to 3 significant figures.

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

Part (a) · 3 marks

Expand and simplify (2x − 1)(x + 3)(x − 5).

  1. 1(2x − 1)(x + 3) = 2x² + 6x − x − 3 = 2x² + 5x − 3
  2. 2(2x² + 5x − 3)(x − 5) = 2x³ − 10x² + 5x² − 25x − 3x + 15
  3. 3Collect like terms: 2x³ − 5x² − 28x + 15

Answer2x³ − 5x² − 28x + 15

Part (b) · 3 marks

Solve 3x² + 6x − 5 = 0, showing working, with solutions to 3 significant figures.

  1. 1Use the formula with a = 3, b = 6, c = −5
  2. 2x = (−6 ± √(6² − 4 × 3 × (−5))) / (2 × 3) = (−6 ± √96) / 6
  3. 3√96 = 9.798…, so x = 3.798… ÷ 6 or x = −15.798… ÷ 6
  4. 4To 3 s.f.: 0.633, −2.63

Answer0.633, −2.63

Stuck on a step? Read the free lesson: Expand and Simplify

Practise more expand and simplify questions

Real 4MA1 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 expand and simplify

Also searched as: 4MA1 1H June 2018 · 4MA1/1H · 4ma1 jun18 1h · question 11.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.