s="co"># expansion by cofactors of row 1</span></span></span>
<span class="r-in"><span><span class="va">M</span><span class="op">[</span><span class="fl">1</span>,<span class="op">]</span> <span class="op"><a href="https://rdrr.io/r/base/matmult.html" class="external-link">%*%</a></span> <span class="fu">rowCofactors</span><span class="op">(</span><span class="va">M</span>,<span class="fl">1</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>      [,1]</span>