%% 
%%  An UIT Edition example
%% 
%%  Example 10-07-3 on page 212.
%% 
%%  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}
\usepackage[utf8]{inputenc}
\AtBeginDocument{\setlength\parindent{0pt}}
\setcounter{equation}{10}
\renewcommand\theequation{10.\arabic{equation}}
\StartShownPreambleCommands
\usepackage{amsmath,color} \AtBeginDocument{% da sonst nicht wirksam!
\addtolength\abovedisplayshortskip{-7mm}\addtolength\abovedisplayskip{-7mm}}
\StopShownPreambleCommands
\begin{document}
Now there is some completely pointless text with completely pointless
    content that is only here to show that there is no problem with the
    {\color{red}colour}.
\begin{align}
\hphantom{\mbox{$f(x)-g(x)$}} & \hphantom{\mbox{$= x^2+x^3+x^4+x^5+b$}}\nonumber\\
f(x) &= a\\ g(x) &= x^2-4x
\end{align}
Now there is some completely pointless text with completely pointless
    content that is only here to show that there is no problem with the
    {\color{red}colour}.
\begin{align}
\hphantom{\mbox{$f(x)-g(x)$}} & \hphantom{\mbox{$= x^2+x^3+x^4+x^5+b$}}\nonumber\\
f(x)-g(x) &= x^2+x^3+x
\end{align}
Now there is some completely pointless text with completely pointless
    content that is only here to show that there is no problem with the
    {\color{red}colour}.
\begin{align}
\hphantom{\mbox{$f(x)-g(x)$}} & \hphantom{\mbox{$= x^2+x^3+x^4+x^5+b$}}\nonumber\\
g(x) &= x^2+x^3+x^4+x^5+b
\end{align}
Now there is some completely pointless text with completely pointless
    content that is only here to show that there is no problem with the
    {\color{red}colour}.
\end{document}