9

I would like to obtain the following formatting.

enter image description here

Caramdir
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projetmbc
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1 Answers1

11

You could (ab-) use chemmacros's redox macros:

% arara: pdflatex
% arara: pdflatex
\documentclass{scrartcl}
\usepackage{chemmacros}

\begin{document}

\begin{equation}
 \OX{first,$k$}(\OX{second,$a$}+\OX{third,$b$}) = ka + kb
\end{equation}
\redox(first,second)[->]{$\times$}
\redox(first,third)[->][-1]{$\times$}

\end{document}

enter image description here

cgnieder
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    Neat! Just a quick suggestion -- if you prefixed \scriptsize to the two instances of $\times$, the multiplication symbol's size would be (slightly) better proportioned. – Mico Jun 24 '12 at 12:11
  • Sure, why not. I simply wanted to demonstrate the basic principle. :) – cgnieder Jun 24 '12 at 14:30