\(A=\begin{bmatrix}5&0&4\\2&3&2\\1&2&1\end{bmatrix},\)\(B^{-1}=\begin{bmatrix}1&3&3\\1&4&3\\1&3&4\end{bmatrix}\)
Here , (AB) –1 = B –1 A –1
|A| = – 5 + 4 = – 1
Cofactors of A are:
C11 = – 1 C21 = 8 C31 = – 12
C12 = 0 C22 = 1 C32 = – 2
C13 = 1 C23 = – 10 C33 = 15