In each part, find the matrix X solving the given equation.
a.   $\left[\begin{array}{cc} -6 &0\cr 0 &1 \end{array}\right] X = \left[\begin{array}{cc} 2 &-7\cr 6 &10 \end{array}\right].$   $X =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

b.   $\left[\begin{array}{cc} 0 &1\cr 1 &0 \end{array}\right] X = \left[\begin{array}{cc} 1 &-6\cr 5 &-2 \end{array}\right]$.   $X =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

c.   $\left[\begin{array}{cc} 1 &2\cr 0 &1 \end{array}\right] X = \left[\begin{array}{cc} -2 &5\cr 6 &2 \end{array}\right]$.   $X =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

d.   $\left[\begin{array}{cc} 1 &-3\cr 4 &-11 \end{array}\right] X = \left[\begin{array}{cc} -6 &7\cr 8 &8 \end{array}\right]$.   $X =$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

e.   $\left[\begin{array}{ccc} 1 &0 &0\cr 0 &1 &0\cr 0 &0 &-3 \end{array}\right] X = \left[\begin{array}{ccc} 5 &5 &1\cr 2 &8 &-2\cr -8 &-8 &9 \end{array}\right]$.

  $X =$ $\left[\Rule{0pt}{3.6em}{0pt}\right.$$\left]\Rule{0pt}{3.6em}{0pt}\right.$

f.   $\left[\begin{array}{ccc} 0 &0 &1\cr 0 &1 &0\cr 1 &0 &0 \end{array}\right] X = \left[\begin{array}{ccc} 6 &7 &9\cr -6 &-8 &-5\cr -7 &-5 &3 \end{array}\right]$.

  $X =$ $\left[\Rule{0pt}{3.6em}{0pt}\right.$$\left]\Rule{0pt}{3.6em}{0pt}\right.$

g.   $\left[\begin{array}{ccc} 1 &0 &0\cr 0 &1 &0\cr 0 &10 &1 \end{array}\right] X = \left[\begin{array}{ccc} 1 &5 &-2\cr -2 &4 &-10\cr -9 &-5 &3 \end{array}\right]$.

  $X =$ $\left[\Rule{0pt}{3.6em}{0pt}\right.$$\left]\Rule{0pt}{3.6em}{0pt}\right.$