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If $A$ be a $3 \times 3$ square matrix such that $A(\text{adj } A) = \begin{bmatrix} 5 & 0 & 0 \\ 0 & 5 & 0 \\ 0 & 0 & 5 \end{bmatrix}$ then the value of $|\text{adj } A|$ is |
5 25 125 625 |
25 |
The correct answer is Option (2) → 25 ## $A(\text{adj } A) = 5I$ $A(\text{adj } A) = |A|I$ $∴|A| = 5$ $|\text{adj } A| = |A|^{n-1} = |A|^2 = 25$ |
