%%
%% An UIT Edition example
%%
%% Example 10-10-1 on page 222.
%%
%% Copyright (C) 2010 Herbert Voss
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3
%% of this license or (at your option) any later version.
%%
%% See
http://www.latex-project.org/lppl.txt for details.
%%
%%
%% ====
% Show page(s) 1
%%
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{153.70511pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\usepackage{amsmath}
\StopShownPreambleCommands
\begin{document}
\begin {align*}
4x+ 6y -2z &= -4\\
x -y +2z &= 9 \\[-1.4 ex]%
\cline{1-2}
5x + 5y &= 5 \\
x + y &= 1 \\[-1.4 ex]%
\multispan{2}{%
\leaders\hbox{$\mkern-2mu\Relbar\mkern-2mu$}\hfil}\\
y &= 1-x
\end {align*}
\end{document}
