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The positive value of the determinant of the matrix A , whose A d j A d j A = 14 28 - 14 - 14 14 28 28 - 14 14 , is ______.

Correct answer

0

Step-by-step solution

Given, 14 28 - 14 - 14 14 28 28 - 14 14 = adj adj A Now we know that adj A = A 2 if it is 3 × 3 matrix So adj adj A = adj A 2 ⇒ A 2 × 2 = A 4 Now, A 4 = 14 28 - 14 - 14 14 28 28 - 14 14 ⇒       A 4 = 14 3   1 2 - 1 - 1 1 2 2 - 1 1 ⇒ A 4 = 14 3 × 14 A 4 = 14 4     ⇒   A = 14

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