<exercise checkit-seed="0003" 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 & 0 & -1 \\
0 & 1 & -2 & -5 \\
0 & 0 & 1 & 5 \\
0 & 0 & -1 & -4
\end{array}\right] </m>.</p>
</statement>
<answer>
<me>A^{-1}= \left[\begin{array}{cccc}
1 & 1 & -2 & -4 \\
0 & 1 & -3 & -5 \\
0 & 0 & -4 & -5 \\
0 & 0 & 1 & 1
\end{array}\right] </me>
</answer>
</exercise>