%% 
%%  An UIT Edition example
%% 
%%  Example 04-11-2 on page 60.
%% 
%%  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

\StopShownPreambleCommands
\begin{document}
$\begin{array}{r@{\kern1.5pt}c@{\kern1.5pt}c}
     &   & \textrm{factorise}\\
f(x) & = & \underbrace{\overbrace{x^{2}+2x+1}}\\
     &   & \quad\left(x+1\right)^{2}
\end{array}$
\end{document}