Chapter 6.3, Problem 25E

Finding the Inverse of a Matrix Find the inverse of the matrix if it exists.

$\left[\begin{array}{rrrr}\hfill 1& \hfill 2& \hfill 0& \hfill 3\\ \hfill 0& \hfill 1& \hfill 1& \hfill 1\\ \hfill 0& \hfill 1& \hfill 0& \hfill 1\\ \hfill 1& \hfill 2& \hfill 0& \hfill 2\end{array}\right]$