## Elementary Linear Algebra 7th Edition

$$A^{-1}=-\frac{1}{4}\left[ \begin {array}{cccccc} 2&2\\ 3&1\end {array} \right].$$
Since $ad-bc=(1)(2)-(-2)(-3)=2-6=-4\neq 0$, then $A$ has inverse given by $$A^{-1}=-\frac{1}{4}\left[ \begin {array}{cccccc} 2&2\\ 3&1\end {array} \right].$$