# How to write in each line of system of equations after a vertical line

So I have made a system of equations and put the vertical line after it:

But I need to write in each line of system after that vertical line, it should look something lake that: I don't know how to do it, help...

Another solution with two systemes

\documentclass[border=15]{standalone}
\usepackage{systeme}
\begin{document}
$\systeme{2x_1 + 3x_2 - 4x_3 - 2x_4 = 3, 2x_1 + x_2 - x_3 - 3x_4 = 2, 2x_1 + x_3 - 7x_4 = 3, 2x_2 - 3x_3 + x_4 = 1} \sysdelim|.\systeme{,\-I,\-I,}$
\end{document}

You can use the extra column.

\documentclass{article}
\usepackage{amsmath}
\usepackage{systeme}

\newcommand{\bigvrule}{%
\smash{%
\vrule height 1.3\normalbaselineskip depth 0.7\normalbaselineskip width 0.4pt
}%
}

\begin{document}

\begin{equation*}
\syscodeextracol{\enspace}{}
\systeme{
x_1+3x_2-4x_3-2x_4=3  @ \vrule,
2x_1+ x_2- x_3-3x_4=2  @ \bigvrule\;$-I$,
2x_1+      x_3-7x_4=3  @ \bigvrule\;$-I$,
2x_2-3x_3+ x_4=1  @ \vrule
}
\end{equation*}

\end{document}

It's a bit of a hack: the middle rules are higher and deeper so they overlap the first and last.

• Thank You for help! Oct 26, 2022 at 17:23

Perhaps some \rlaps trailed by a \hphantom do the trick:

\documentclass{article}
\usepackage{amsmath}
\usepackage{systeme}

\begin{document}

\begin{equation*}
\syscodeextracol{\enspace}{}
\sysdelim\{|
ZZ\systeme{
x_1+3x_2-4x_3-2x_4=3,
2x_1+ x_2- x_3-3x_4=2 @\rlap{\hbox{\enspace$\left.\right.{-I}$}},
2x_1+      x_3-7x_4=3 @\rlap{\hbox{\enspace$\left.\right.{-I}$}},
2x_2-3x_3+ x_4=1 @\rlap{\hbox{\enspace$\left.\right.{2}$}}% <- don't omit this comment!!!!
}%
\hphantom{%
\vbox{%
%repeat the \hboxes from above:
%  - probably remove \left.\right. from the boxes this time -
\hbox{\enspace$\left.\right.{-I}$}%
\hbox{\enspace$\left.\right.{-I}$}%
\hbox{\enspace$\left.\right.{2}$}%
}%
}%
ZZ
\end{equation*}

\end{document}

A crude attempt without packages:

\begin{document}

$% \left\{% \begin{array}{@{}*3{r@{\mskip\medmuskip}c@{\mskip\medmuskip}}r@{\mskip\thickmuskip}c@{\mskip\thickmuskip}r|l@{}} x_1&+&3x_2&-&4x_3&-&2x_4&=&3&\\ 2x_1&+& x_2&-& x_3&-&3x_4&=&2&-I\\ 2x_1& & &+& x_3&-&7x_4&=&3&-I\\ & &2x_2&-&3x_3&+& x_4&=&1& \end{array} \right.%$%

\end{document}