[tex]\left\{\begin{array}{ccc}1x-8y+1z=-2\\3x-1y+2z=7\\0x+4y-5z=-4\end{array}\right.\\\\\\.\ \ \begin{array}{ccc}x&\ y&\ \ z\end{array}\\\left[\begin{array}{ccc}1&-8&1\\3&-1&2\\0&4&-5\end{array}\right| \left\begin{array}{ccc}-2\\7\\-4\end{array}\right][/tex]
