Class 12 Matrices · Short Answer2 Marksmatrix_linear_combinations
Class 12 Maths · Matrices · Short Answer #94
For A=\(\begin{bmatrix}2 & 4\\3 & 2\end{bmatrix}\) and B=\(\begin{bmatrix}-2 & 5\\3 & 4\end{bmatrix}\), find 3A−B.
✅ Step-by-Step Solution
Final Answer: \(\begin{bmatrix}8 & 7\\6 & 2\end{bmatrix}\)
- First 3A=[[6,12],[9,6]].
- Subtract B entrywise: [[6−(−2),12−5],[9−3,6−4]]=[[8,7],[6,2]].
- Therefore 3A−B=\(\begin{bmatrix}8 & 7\\6 & 2\end{bmatrix}\).
📋 CBSE Stepwise Marking Scheme
- [0.5 marks] First 3A=[[6,12],[9,6]].
- [1 mark] Subtract B entrywise: [[6−(−2),12−5],[9−3,6−4]]=[[8,7],[6,2]].
- [0.5 marks] Therefore 3A−B=\(\begin{bmatrix}8 & 7\\6 & 2\end{bmatrix}\).
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