Skip to main content
O-LevelAdditional MathematicsSimultaneous equations4037/12 · Oct/Nov 2014 · Q76 Marks

Matrices A and B are such that A = ( (3a, 2b), (-a, b) ) and B = ( (-a, b), (2a, 2b) ) where a and b are non-zero constants.

  1. (i)Find A⁻¹.[2]
  2. (ii)Using your answer to part (i), find the matrix X such that XA = B.[4]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2014). The mark or mark type is shown in brackets.

  1. [2] B1 for 1/(5ab), B1 for ( (b, -2b), (a, 3a) )
  2. [1] M1 for post-multiplication by inverse matrix X = BA⁻¹
  3. [1] DM1 for correct attempt at matrix multiplication, needs at least one term correct for their BA⁻¹ (allow unsimplified)
  4. [2] A1 A1 for each correct pair of elements, must be simplified ( (0, 1), (4, 2), (5, 5) )

Write your answer and get it marked

On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.

Sign up free →

About this question

Topic
Simultaneous equations, O-Level Additional Mathematics (syllabus 4037). Structured question, 6 marks.
Source
O-Level Additional Mathematics, Oct/Nov 2014 Paper 1 Variant 2, question 7.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content

Related Additional Mathematics questions

© 2026 Oracle Prep