Answer
$\left[\begin{array}{llll}
2 & 3 & | & 11\\
1 & 2 & | & 8
\end{array}\right]$, dimension:2$\times$3
Work Step by Step
A matrix of dimension n$\times$m has n rows and m columns.
The augmented matrix of the system consists of
the elements of the coefficients matrix to the left,
and the elements of the constants matrix to the right
of (an optional) vertical line:
$\left[\begin{array}{llll}
2 & 3 & | & 11\\
1 & 2 & | & 8
\end{array}\right]$, dimension:2$\times$3