Answer
See below
Work Step by Step
We find the determinant $(ad-bc)$
$35-32=3 $
Use the formula
\[
M=\frac{1}{ad-bc}
\left[ {\begin{array}{cc}
d &-b \\
-c & a \\
\end{array} } \right]
\]
to get
\[
M= 1/3
\left[ {\begin{array}{cc}
-5 & -4 \\
-8 & -7 \\
\end{array} } \right]
\]