Question:
Let \( A=\left[\begin{array}{cccc}1 & 2 & 3 & 4 \\ 5 & 6 & 7 & 8 \\ 9 & 9 & 9 & 9 \\ 8 & 8 & 8 & 8\end{array}\right] \), then determinant of \( A= \)
Let \( A=\left[\begin{array}{cccc}1 & 2 & 3 & 4 \\ 5 & 6 & 7 & 8 \\ 9 & 9 & 9 & 9 \\ 8 & 8 & 8 & 8\end{array}\right] \), then determinant of \( A= \)
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Look at the last two rows: one is a scalar multiple of the other.
Updated On: Nov 12, 2026
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The Correct Option is B
Solution and Explanation
Row 3 is (9, 9, 9, 9) and row 4 is (8, 8, 8, 8).
Row 3 = (9/8) × Row 4, so two rows are proportional.
A determinant with two proportional rows is zero. So |A| = 0.
Answer: (2) 0
Row 3 = (9/8) × Row 4, so two rows are proportional.
A determinant with two proportional rows is zero. So |A| = 0.
Answer: (2) 0
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