%% 
%%  An UIT Edition example
%% 
%%  Example 09-16-8 on page 185.
%% 
%%  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}}
\setcounter{equation}{17}
\renewcommand\theequation{9.\arabic{equation}}
\StartShownPreambleCommands
\usepackage{amsmath,gauss}
\newcommand*\diff{\mathop{}\!\mathrm{d}}
\setlength\arraycolsep{1.4pt}
\renewcommand\rowmultlabel[1]{\left|\,#1\right.}
\newcommand*\xstrut{\rule{0pt}{5ex}}
\StopShownPreambleCommands
\begin{document}
\begin{equation}
\renewcommand\arraystretch{1.8}
\begin{gmatrix}
 \dfrac{1}{C}\int i\times\diff t+L\times\dfrac{\diff i}{\diff t}
               +R\times i\hfill &= & 0\\
 \xstrut\dfrac{1}{C}\times i+L\times\dfrac{\diff ^2i}{\diff t^2}+
     R\times\dfrac{\diff i}{\diff t}\hfill &= &0\\
 \xstrut\dfrac{\diff ^2i}{\diff t^2}+\dfrac{R}{L}\times\dfrac{\diff i}{\diff t}+
    \dfrac{1}{LC}\times i\hfill &= & 0\\
 \xstrut\ddot{i}+\delta\dot{i}+\omega_0^2i\hfill & = &0
 \rowops
 \mult{0}{\mbox{differentiation}}  \mult{1}{:L\mbox{ and sorting}}
 \mult{2}{\dfrac{R}{L}=\delta;\ \dfrac{1}{LC}=\omega_0^2}
\end{gmatrix}
\end{equation}
\end{document}