*noob* LaTeXiT long division

Question

Like it says in the title I'm a complete noob trying to get LaTeXiT to do a simple long division sum.

I've installed the complete latex package I've obtained from here https://tug.org/mactex/mactex-download.html

Like it says I'm a complete noob I need someone to walk me through this step-by-step I'm not familiar with any of the code etc..

I'm already way behind on all my work.

Thanks Brett

Picture of what the output should look like:

Answer 1

What you are writing seems to be close to a tabular. Why don't you go for an easy approach:

\documentclass[pagesize, english]{scrartcl}
\usepackage[T1]{fontenc}\usepackage[utf8]{inputenc}
\usepackage{babel, array, booktabs, ragged2e}

\begin{document}

\begin{tabular}{*{8}{>{\Centering}p{1cm}}}
  & & & $+x^4$ & $+x^3$ & & & $+1$\\\midrule
  $+x^7$ & $+x^6$ & $+x^5$ & & & $+x^2$ &$+x$ & \\
  $+x^7$ &  & $+x^5$ & $+x^4$ & & $+x^2$ &$+x$ & \\\cmidrule{1-4}
  \multicolumn{8}{l}{\dots}
\end{tabular}

\end{document}

And so on... Beware, I've no idea about mathematics! You'll get the manual of any package by texdoc packagenameon the command line.

Answer 2

It is not ideal, because tabstackengine does not have cell underlining/fill facilities built in. (see ADDENDUM for the beginnings of a remedy to that)

\documentclass{article}
\usepackage{tabstackengine,mathtools}
\stackMath
\setstacktabbedgap{1.5ex}
\setstackgap{S}{3pt}
\newcommand\showdiv[1]{\smash{\raisebox{1.5pt}{\scalebox{1.15}{)}}}#1}
\newcommand\laprule[1]{\rlap{\rshift\smash{\rule[-1pt]{#1}{.5pt}}}}
\makeatletter
\newcommand\rshift[1][0pt]{\hspace{\dimexpr#1+\tabbed@gap\relax}}
\makeatother
\begin{document}
\[
\tabbedShortstack[r]{
&  &  &  & +x^4 & +x^3 & &  & +1\\
\laprule{188pt}&&&&&&&&\\
x^3 + x + 1 & \showdiv{{+}x^7} & +x^6 & +x^5 &&&+x^2 & +x & \\
& +x^7 && +x^5 & +x^4&&&&\\
\laprule{97pt}&&&&&&&&\\
&& +x^6 && +x^4 &&&&\\
&& +x^6 && +x^4 & +x^3&&&\\
&\laprule{94pt}&&&&&&&\\
&&&&& +x^3 & +x^2 & +x&\\
&&&&& +x^3 && +x  &+1\\
&&&&\laprule{84pt}&&&&\\
&&&&&& +x^2 &  &+1
}
\]
\end{document}

ADDENDUM

I've been meaning, for a while, to create the TABstack equivalent of \hline and \cline. This will alleviate the need to estimate actual lengths for lapped underlines. This seemed like a good problem on which to start. I have, for the moment, built the underlying \TABrule which, at this time needs to be called in each field where it is used. Eventually, I hope to be able to build a \TABhline and \TABcline which will construct a string of \TABrule& combinations to make the syntax shorter. But here it is so far. If successful, I will implement into the tabstackengine package.

\documentclass{article}
\usepackage{tabstackengine,mathtools}
\stackMath
\setstacktabbedgap{1.5ex}
\setstackgap{S}{3pt}
\newcommand\showdiv{\llap{\smash{\raisebox{1.8pt}{\scalebox{1}[1.2]{)}}}}}
\newcommand\laprule[1]{\rlap{\rshift\smash{\rule[-1pt]{#1}{.5pt}}}}
\makeatletter
\newcommand\rshift[1][0pt]{\hspace{\dimexpr#1+\tabbed@gap\relax}}
\makeatother
%%%%%%%%%%%%%
\makeatletter
\def\trao{0pt}
\newcommand\TABrule[1][\trao]{%
  \ifnum1=\value{TABcolindex@}\relax%
    \makebox[\TABwd{\theTABcolindex@}][l]{%
      \rule[\trao]{\dimexpr\TABwd{\theTABcolindex@}+.5\dimexpr\TAB@gap\relax}{\fboxrule}}%
  \else%
    \ifnum\TABcells{1}=\value{TABcolindex@}\relax%
      \makebox[\TABwd{\theTABcolindex@}][r]{%
        \rule[\trao]{\dimexpr\TABwd{\theTABcolindex@}+.5\dimexpr\TAB@gap\relax}{\fboxrule}}%
    \else%
      \makebox[\TABwd{\theTABcolindex@}][c]{%
        \rule[\trao]{\dimexpr\TABwd{\theTABcolindex@}+1.\dimexpr\TAB@gap\relax}{\fboxrule}}%
    \fi%
  \fi%
}
\newcommand\set@TABrule@gap[1]{%
  \ifstrequal{#1}{D}{\def\TAB@gap{\tabbed@gap}}{%
      \ifstrequal{#1}{A}{\def\TAB@gap{0pt}}{\def\TAB@gap{\tabular@gap}}%
  }%
}
\usepackage{xpatch}
\xpatchcmd{\@TAB@stack}{\bgroup}{\bgroup\set@TABrule@gap{#3}}{}{}
\xpatchcmd{\@TABstackonunder}{\bgroup}{\bgroup\set@TABrule@gap{#4}}{}{}
\makeatother
%%%%%%%%%%%%%
\begin{document}
\[
\tabbedShortstack[r]{
&  &  &  & +x^4 & +x^3 & &  & +1\\
&\TABrule&\TABrule&\TABrule&\TABrule&\TABrule&\TABrule&\TABrule&\TABrule\\
x^3 + x + 1 & \showdiv{+}x^7 & +x^6 & +x^5 &&&+x^2 & +x & \\
& +x^7 && +x^5 & +x^4&&&&\\
&\TABrule&\TABrule&\TABrule&\TABrule&&&&\\
&& +x^6 && +x^4 &&&&\\
&& +x^6 && +x^4 & +x^3&&&\\
&&\TABrule&\TABrule&\TABrule&\TABrule&&&\\
&&&&& +x^3 & +x^2 & +x&\\
&&&&& +x^3 && +x  &+1\\
&&&&&\TABrule&\TABrule&\TABrule&\TABrule\\
&&&&&& +x^2 &  &+1
}
\]
\end{document}