MHT CET · Maths · Matrices
If \(A=\left[\begin{array}{ccc}1 & 3 & -2 \\ -3 & 0 & -5 \\ 2 & 5 & 0\end{array}\right]\) and \(A(\operatorname{adj} A)=K I\), then the value of \(K\) is (where \(I\) is unit matrix of order 3)
- A \(-25\)
- B \(25\)
- C \(85\)
- D \(-85\)
Answer & Solution
Correct Answer
(B) \(25\)
Step-by-step Solution
Detailed explanation
\(
\because A(\operatorname{adj} A)=|A| . I
\)
Hence \(\mathrm{K}=|\mathrm{A}|=25\)
\because A(\operatorname{adj} A)=|A| . I
\)
Hence \(\mathrm{K}=|\mathrm{A}|=25\)
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