WMA12/01 Jan 2024, Question 2: The Binomial Expansion
Pearson Edexcel International AS Level Mathematics · Pure Mathematics 2 (WMA12) · Calculator · 3 marks
The question, in short
Find the coefficient of x⁷ in the binomial expansion of (3/8 + 4x)¹², giving the answer in simplest form.
Summarised in our own words. Use the official paper for the exact wording and any diagrams.
Solution · 3 marks
- 1The x⁷ term is ¹²C₇ (3/8)⁵ (4x)⁷
- 2¹²C₇ = 792
- 3(3/8)⁵ = 243/32768 and 4⁷ = 16384
- 4Coefficient = 792 × 243/32768 × 16384 = 792 × 243/2 = 96228
Answer96228
Stuck on a step? Read the free lesson: The Binomial Expansion
Practise more the binomial expansion questions
Real XMA01 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 binomial expansion
Also searched as: WMA12 January 2024 · WMA12/01 · wma12 jan24 · IAS Maths Pure Mathematics 2 January 2024 · question 2.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.