COMEDK · Maths · 21. Matrices
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The above situation can be represented in matrix form as \(A X=B\).
Then \(|\operatorname{adj} A|\) is equal to
- A \(-1\)
- B \(1\)
- C \(-9\)
- D \(9\)
Answer & Solution
Correct Answer
(B) \(1\)
Step-by-step Solution
Detailed explanation
Coefficient matrix: \(A = \begin{bmatrix} 3 & 2 & 1 \\ 2 & 1 & 2 \\ 3 & 2 & 2 \end{bmatrix}\) Applying \(R_3 \to R_3 - R_1\): \(|A| = \begin{vmatrix} 3 & 2 & 1 \\ 2 & 1 & 2 \\ 0 & 0 & 1 \end{vmatrix}\) Expanding along \(R_3\):…
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