Question

1
6. If A =
2 1 - 2 . show that adj. A = 3A.
2 - 2
1
1
2 3 4
7. If A = 3 0 1
2 1 5
verify that A. (adj. A) = (adj. A). A = A.1.
2 1 3
8. If A = 3 1 2
verify that A (adj. A) = (adj. A). A = |Al.I.
1 2 3
1 2 3
9. If A = 2 3 2
verify that A. (adj. A) = (adj. A). A = |A|.1.
3
3 3 4
ANSWERS​

Answer 1

Answer:

If A=

⎣

⎢

⎢

⎡

−1

2

2

−2

1

−2

−2

−2

1

⎦

⎥

⎥

⎤

, show that adjA=3A

′

.