Given the matrices in Problems 32-35, perform elementary row operations to obtain a 1 in the third row, third column without changing the entries in the first two columns.

\([\mathrm{C}]=\left[\begin{array}{rrrr:r}1 & 0 & -2 & 1 & 1 \\ 0 & 1 & 6 & 2 & 0 \\ 0 & 0 & 4 & 0 & -2 \\ 0 & 0 & 2 & 1 & 0\end{array}ight]\)