Perform the row operation $R_{1} \leftrightarrow R_{2}$ on the matrix below. \[ \left[\begin{array}{rr|r} 1 & -6 & 4 \\ 5 & -9 & -6 \end{array}\right] \]

Step 1 ：Perform the row operation $R_{1} \leftrightarrow R_{2}$ on the matrix \[\left[\begin{array}{rr|r} 1 & -6 & 4 \\ 5 & -9 & -6 \end{array}\right]\] which means to swap the first row with the second row.

Step 2 ：The resulting matrix is \[\left[\begin{array}{rr|r} 5 & -9 & -6 \\ 1 & -6 & 4 \end{array}\right]\]

Step 3 ：Final Answer: \[\boxed{\left[\begin{array}{rr|r} 5 & -9 & -6 \\ 1 & -6 & 4 \end{array}\right]}\]