If $A = \left[\begin{array}{ccc} -3 &-6 &13\cr 1 &3 &-6\cr -1 &-2 &4 \end{array}\right]$, then

$A^{-1} =$ $\left[\Rule{0pt}{3.6em}{0pt}\right.$$\left]\Rule{0pt}{3.6em}{0pt}\right.$.