# How to typeset and annotate a polynomial long division

I need to type a paper for a teacher, who hasn't seen the European division method, so that she could possibly use it in her curriculum.

I need something to look like this

x^2+4x+4       Box(x+2)
-(x^2 + 2x)
----------------
2x+4
-(2x + 4)
-----------------
0


## 2 Answers

Here is one way to do this:

## Notes:

• The booktabs package was used to provide flexible horizontal rules.
• The \Ph macro uses \hphantom{)} to insert a horizontal space equivalent to the closing bracket to get things all aligned.

## Code:

\documentclass{article}
\usepackage{amsmath}
\usepackage{booktabs}
\usepackage{array}
\newcommand*{\Ph}{\hphantom{)}}%
\begin{document}
$\begin{array}{r@{} r@{} r r} x^2 &{}+4x\Ph&{}+4\Ph &\fbox{$(x+2)$} \\ -(x^2 &{}+ 2x) &\\ \cmidrule{1-2} & 2x\Ph &{}+4\Ph\\ &-(2x\Ph &{}+4) \\ \cmidrule{2-3} & &0\Ph \end{array}$
\end{document}

• Thanks but how do I get an actual box for the x+2? I really appreciate your help. My gratitude. – Person Nov 9 '12 at 1:46
• @Person: Use \boxed{($x+2$)}  with amsmath loaded. – user11232 Nov 9 '12 at 1:48
• @HarishKumar: I was not aware of \boxed, but that seems to force the text inside the box to be in \text mode somehow even with , so used \fbox instead. – Peter Grill Nov 9 '12 at 1:53
• @PeterGrill: \boxed is defined by amsmath for mathmode. There is a similar \Aboxed in mathtools. If you use \boxed{(x+2)}, then it will be in mathmode. Don't use $. – user11232 Nov 9 '12 at 2:17 • @HarishKumar: Thanks. I am familiar with \Aboxed form my very first question posted on TeX.SE. But, am surprised that \boxed{$(x+2)\$} compiled with x in text mode -- seems like a bug? – Peter Grill Nov 9 '12 at 2:43

Try looking at the package polynom.sty (CTAN, TeXdoc). It can even do the division for you.