If $$A = \left[\begin{array}{cccc} -3 &5 &1 &-5\cr 0 &1 &2 &-2\cr 0 &0 &-3 &1\cr 0 &0 &0 &3 \end{array}\right],$$ then
$A^{-1} =$ $\left[\Rule{0pt}{4.8em}{0pt}\right.$$\left]\Rule{0pt}{4.8em}{0pt}\right.$.