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Question
Without expanding evaluate the following determinant:
`|(2, 3, 4),(5, 6, 8),(6x, 9x, 12x)|`
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Solution
Let D = `|(2, 3, 4),(5, 6, 8),(6x, 9x, 12x)|`
Taking (3x) common from R3, we get
D = `3x|(2, 3, 4),(5, 6, 8),(2, 3, 4)|`
= (3x)(0) ...[∵ R1 and R3 are identical]
= 0
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