0001.ptx

<exercise checkit-seed="0001" checkit-slug="G1" checkit-title="Row operations and determinants">
  <statement>
    <p>Let <m>A</m> be a <m>4 \times 4</m> matrix with determinant <m> -4 </m>.</p>
    <ol>
      <li>Let <m>N</m> be the matrix obtained from <m>A</m> by applying the row operation <m> R_4 \to -5R_4 </m>.
              What is <m>\operatorname{det}\ N</m>?</li>
      <li>Let <m>P</m> be the matrix obtained from <m>A</m> by applying the row operation <m> R_3 \to R_3 + -3R_2 </m>.
              What is <m>\operatorname{det}\ P</m>?</li>
      <li>Let <m>C</m> be the matrix obtained from <m>A</m> by applying the row operation <m> R_4 \leftrightarrow R_3 </m>.
              What is <m>\operatorname{det}\ C</m>?</li>
    </ol>
  </statement>
  <answer>
    <ol>
      <li>
        <m>\operatorname{det}\ N= 20 </m>
      </li>
      <li>
        <m>\operatorname{det}\ P= -4 </m>
      </li>
      <li>
        <m>\operatorname{det}\ C= 4 </m>
      </li>
    </ol>
  </answer>
</exercise>