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Given that A is a square matrix of order 3 and |A| = –2, then |adj(2A)| is equal to ______. - Mathematics

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Question

Given that A is a square matrix of order 3 and |A| = –2, then |adj(2A)| is equal to ______.

Options

  • –26

  • +4

  • –28

  • 28

MCQ
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Solution

Given that A is a square matrix of order 3 and |A| = –2, then |adj(2A)| is equal to 28.

Explanation:

|adj(2A)| = |(2A)|2

= (23 |A|)2

= 26 |A|2

= 26 × (–2)2

= 28.

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