Class 12 Matrices · Short Answer2 Marksmatrix_equality
Class 12 Maths · Matrices · Short Answer #59
For A=\(\begin{bmatrix}0 & 3\\2 & -5\end{bmatrix}\) and kA=\(\begin{bmatrix}0 & 4a\\-8 & 5b\end{bmatrix}\), find k,a,b.
✅ Step-by-Step Solution
Final Answer: k=−4,a=−3,b=4
- The left side is kA=[[0,3k],[2k,−5k]]; compare it with the given matrix [[0,4a],[−8,5b]].
- Comparing entries gives 2k=−8, 3k=4a and −5k=5b. Thus k=−4,a=−3,b=4.
- Therefore (k,a,b)=(−4,−3,4).
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] The left side is kA=[[0,3k],[2k,−5k]]; compare it with the given matrix [[0,4a],[−8,5b]].
- [1 mark] Comparing entries gives 2k=−8, 3k=4a and −5k=5b. Thus k=−4,a=−3,b=4.
- [0.5 marks] Therefore (k,a,b)=(−4,−3,4).
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