0011.ptx

<exercise checkit-seed="0011" checkit-slug="M4" checkit-title="Finding a matrix inverse">
  <statement>
    <p>Show how to find the inverse of the matrix <m>B= \left[\begin{array}{cccc}
1 &amp; 3 &amp; 3 &amp; -7 \\
0 &amp; 1 &amp; 2 &amp; -4 \\
0 &amp; 0 &amp; 1 &amp; -3 \\
0 &amp; 3 &amp; 5 &amp; -8
\end{array}\right] </m>.</p>
  </statement>
  <answer>
    <me>B^{-1}= \left[\begin{array}{cccc}
1 &amp; -15 &amp; 7 &amp; 4 \\
0 &amp; 7 &amp; -4 &amp; -2 \\
0 &amp; -9 &amp; 4 &amp; 3 \\
0 &amp; -3 &amp; 1 &amp; 1
\end{array}\right] </me>
  </answer>
</exercise>