Vertical line in Gaussian reduction matrix

Question

Try to represent Gaussian reduction in Latex but couldn't find way to correctly show the vertical line

\begin{pmatrix}[cc|c]
  1 & 2 & 3\\
  4 & 5 & 9
\end{pmatrix}

doesn't work

This works for me

$$\left(\begin{array}{cc|c}  
 1 & 1 & -1 \\  
 2 & 3 & 0  \\ 
\end{array}\right)
$$

Answer 1

You can have this simpler code with delarray:

\documentclass{article}
\usepackage{amsmath}
 \usepackage{delarray}

\begin{document}

\[
    \begin{array}({@{}cc|c@{}})
     1 & 1 & -1 \\
     2 & 3 & 0 \\
    \end{array}\
\]

\end{document}