If 2X + [[1, 0], [0, 1]] = [[5, 2], [4, 3]], what is X?
Correct answer: A. [[2, 1], [2, 1]]
- A. [[2, 1], [2, 1]]
- B. [[3, 1], [2, 2]]
- C. [[2, 2], [1, 1]]
- D. [[4, 2], [4, 2]]
Explanation
Subtract the identity matrix from the right side to obtain [[4, 2], [4, 2]], then divide every entry by 2. This gives X = [[2, 1], [2, 1]].
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
Practise Simultaneous Equations and Matrices
30 free Simultaneous Equations and Matrices MCQs from Quantitative Methods, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Quantitative Methods questions like this
Quantitative Methods is on this paper prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for it.
More Simultaneous Equations and Matrices questions
A consistent system has three linear equations in two unknowns. Which rank condition gives it a unique solution?
What is the determinant of the matrix [[2, 1, 0], [1, 3, 2], [0, 2, 1]]?
Which matrix acts as the multiplicative identity for every 2 × 2 matrix A?
For a 2 × 2 matrix [[a, b], [c, d]], which expression represents its inverse when ad - bc is nonzero?
In Cramer's rule for two equations in x and y, how is the determinant used to find x?
A consistent homogeneous system has fewer independent equations than unknowns. What can be concluded about its solutions?