%% 
%%  An UIT Edition example
%% 
%%  Example 05-03-1 on page 74.
%% 
%%  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}
\setlength\parindent{0pt}
\StartShownPreambleCommands
\usepackage{xcolor,amsmath}
\def\xstrut{\vphantom{\dfrac{(A)^1}{(B)^1}}}
\StopShownPreambleCommands
\begin{document}
\[ E = \colorbox{lightgray}{$\xstrut a_vA$} -
       \colorbox{magenta!30}{$\xstrut a_fA^{2/3}$} -
       \colorbox{green!60}{$\xstrut a_c\dfrac{Z(Z-1)}{A^{1/3}}$} -
       \colorbox{cyan}{$\xstrut a_s\dfrac{(A-2Z)^2}{A}$} +
       \colorbox{yellow}{$\xstrut E_p$} \]
\end{document}