We have,

We have to find A^-1 and

Firstly, we find |A|

Expanding |A| along C₁, we get

= 1(1 – (-3)) – 1(-2 – 15) + 2(-2 – (-5))

= (1 + 3) – 1(-17) + 2(-2 + 5)

= 4 + 17 + 2(3)

= 21 + 6

= 27

Now, we have to find adj A, and for that, we have to find co-factors:

Ans.