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Mathematics · JEE | DETERMINANTS
हिन्दीIf the determinant \( \Delta = \begin{vmatrix} 2 & 4 \\ -1 & 2 \end{vmatrix} \) and \( A \) is a matrix of order \( 2 \times 2 \) such that \( |A| = \Delta \), then the value of \( |3A| - |2A| \) is equal to:
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Correct answer · Option C
"40"
Explanation
\( \Delta = 2(2) - 4(-1) = 8 \). For order \( 2 \times 2 \), \( |kA| = k^2 |A| \). Hence \( |3A| - |2A| = (3^2 - 2^2)|A| = (9 - 4)(8) = 5 \times 8 = 40 \).
