<exercise checkit-seed="0010" checkit-slug="M4" checkit-title="Finding a matrix inverse">
<statement>
<p>Show how to find the inverse of the matrix <m>A= \left[\begin{array}{cccc}
1 & -1 & 3 & 5 \\
0 & 1 & -5 & -8 \\
0 & 0 & 1 & 2 \\
0 & 1 & -3 & -3
\end{array}\right] </m>.</p>
</statement>
<answer>
<me>A^{-1}= \left[\begin{array}{cccc}
1 & 2 & 4 & -1 \\
0 & 3 & 9 & -2 \\
0 & 2 & 5 & -2 \\
0 & -1 & -2 & 1
\end{array}\right] </me>
</answer>
</exercise>