%% 
%%  An UIT Edition example
%% 
%%  Example 04-08-7 on page 54.
%% 
%%  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{375.57637pt}
\AtBeginDocument{\setlength\parindent{0pt}}
\StartShownPreambleCommands
\usepackage{tabularx}
\StopShownPreambleCommands
\begin{document}
\begin{tabularx}{\linewidth}{@{}XXX@{}}
\begin{eqnarray*}
y & = & d\\ y & = & c\frac{1}{x}+d\\ y & = & b\frac{1}{x^{2}}+cx+d
\end{eqnarray*}
&
\setlength\jot{0pt}
\begin{eqnarray*}
y & = & d\\ y & = & c\frac{1}{x}+d\\ y & = & b\frac{1}{x^{2}}+cx+d
\end{eqnarray*}
&
\setlength\jot{10pt}
\begin{eqnarray*}
y & = & d\\ y & = & c\frac{1}{x}+d\\ y & = & b\frac{1}{x^{2}}+cx+d
\end{eqnarray*}
\end{tabularx}
\end{document}