If A is a 3 × 3 matrix, |A| ≠ 0 and |3A| = k|A| then write value of k.

We are given that,

Order of matrix = 3


|A| ≠ 0


|3A| = k|A|


We need to find the value of k.


In order to find k, we need to solve |3A|.


Using property of determinants,


|kA| = kn|A|


Where, order of A is n × n.


Similarly,


|3A| = 33|A|


[, order of A is 3]


|3A| = 27|A| …(i)


As, according to the question


|3A| = k|A|


Using (i),


27|A| = k|A|


Comparing the left hand side and right hand side, we get


k = 27


Thus, the value of k is 27.


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