%% 
%%  An UIT Edition example
%% 
%%  Example 03-05-1 on page 25.
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%%  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
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\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{201.70511pt}
\setlength\parindent{0pt}
\usepackage[english]{babel}
\setcounter{equation}{22}
\renewcommand\theequation{3.\arabic{equation}}
\StartShownPreambleCommands

\StopShownPreambleCommands
\begin{document}
\begin{eqnarray}
y & = & d     \label{eq:2}\\
y & = & cx+d\\
y & = & bx^{2}+cx+d\\
y & = & ax^{3}+bx^{2}+cx+d\label{eq:5}
\end{eqnarray}
In the coding we gave equations~\ref{eq:2}
and~\ref{eq:5} a label so that they could
be referred to in the text.
\end{document}