4MA1/1H Jun 2021, Question 21: Algebraic Fractions
Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1H (Higher) · Calculator · 4 marks
اقرأ هذا الحل مشروحاً بالعربي ←
The question, in short
Given x = 5/(9y + 5) and y = 5/(5a − 2), find x in terms of a as a single simplified fraction.
Summarised in our own words. Use the official paper for the exact wording and any diagrams.
Solution · 4 marks
- 1Substitute y = 5/(5a − 2) into x = 5/(9y + 5)
- 29y = 45/(5a − 2), so the bottom is 45/(5a − 2) + 5
- 3Write it over one denominator: (45 + 5(5a − 2))/(5a − 2)
- 445 + 25a − 10 = 35 + 25a, so the bottom is (35 + 25a)/(5a − 2)
- 5Dividing by a fraction turns it over: x = 5(5a − 2)/(35 + 25a)
- 635 + 25a = 5(7 + 5a), so the 5s cancel
- 7x = (5a − 2)/(7 + 5a)
Answer(5a − 2)/(7 + 5a)
Stuck on a step? Read the free lesson: Algebraic Fractions
Practise more algebraic fractions questions
Real 4MA1 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 algebraic fractions
Also searched as: 4MA1 1H June 2021 · 4MA1/1H · 4ma1 jun21 1h · question 21.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.