Answer
$\left[\begin{array}{lllll}
2 & 1 & 4 & | & -4\\
3 & 0 & 1 & | & 1\\
4 & 3 & 1 & | & 8
\end{array}\right]$
Work Step by Step
See text under "Augmented Matrices" on p.590.
In an augmented matrix, a vertical bar (line) separates two groups of elements.
Each row of the augmented matrix has
coefficients of x, y, z on the left of the vertical line, and
constants to the right of the vertical line
$\left[\begin{array}{lllll}
2 & 1 & 4 & | & -4\\
3 & 0 & 1 & | & 1\\
4 & 3 & 1 & | & 8
\end{array}\right]$
