Let $$A= \left[\begin{array}{ccc} 2 &-1 &3\cr 3 &0 &-9 \end{array}\right].$$ Perform the following row operations sequentially (applying each new operation to the previous result).

First, swap the first and second rows:
$\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

Second, multiply every element of the first row by $\displaystyle \frac{1}{3}$:
$\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$

Third: add to the elements of the second row, $-2$ times the corresponding elements of the first row:
$\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$