Compute the following products.

$\left[\begin{array}{cc} -6 &1\cr -6 &5 \end{array}\right] \left[\begin{array}{c} 9\cr -5 \end{array}\right] =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

$\left[\begin{array}{cc} -6 &1\cr -6 &5 \end{array}\right] \left[\begin{array}{c} 1\cr 4 \end{array}\right] =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

$\left[\begin{array}{cc} -6 &1\cr -6 &5 \end{array}\right] \left[\begin{array}{cc} 9 &1\cr -5 &4 \end{array}\right] =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$