4.7 Exercise 128

Perform the indicated operations on the augmented matrices.

$\left[\right. \begin{aligned}1 & & & −3 & & & −2 \\ 2 & & & 2 & & & −1 \\ 4 & & & −2 & & & −3\end{aligned} \left|\right. \begin{matrix}4 \\ −3 \\ −1\end{matrix} \left]\right.$

ⓐ Interchange rows 2 and 3.
ⓑ Multiply row 1 by 2.
ⓒ Multiply row 3 by $−2$ and add to row 2.