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Let A be a square matrix of order 3 and ∣A∣=−3|A| = -3, then ∣adj(3A)∣|adj(3A)| is equal to:

Solution

✅ Correct Option: 1

For order 33, ∣3A∣=33∣A∣=27(−3)=−81|3A| = 3^3|A| = 27(-3) = -81.

Also ∣adj M∣=∣M∣n−1=∣M∣2|adj\,M| = |M|^{n-1} = |M|^2, so ∣adj(3A)∣=(−81)2=6561=38|adj(3A)| = (-81)^2 = 6561 = 3^8.

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