I am trying to get two sets of equations to show up in line with the text width in a minipage environment, however, I am not getting the correct output. The second minipage goes outside the textwidth. Here is my code:

```
\documentclass[11pt,fleqn]{book}
\usepackage{empheq}
\begin{document}
\begin{minipage}[l]{.5\textwidth}
\begin{align}
\Delta T_{DEAD-ZONE}&=\frac{A_{1}}{A_{2}}\\
\Delta T_{DEAD-ZONE}&=\frac{A_{3}}{A_{4}}\\
\Delta \theta_{DEAD-ZONE}&=\frac{A_{5}}{A_{6}}~radians
\end{align}
\end{minipage}
\begin{minipage}{0.5\textwidth}
\begin{align*}
\mbox{where}\begin{cases}
A_{1}&=\quad\mbox{Peak VCO Phase Deviation}\\
A_{2}&=\quad\mbox{Modulation Frequency}\\
A_{3}&=\quad\mbox{peak VCO freq. Deviation}\\
A_{4}&=\quad\mbox{Reference Frequency}\\
A_{5}&=\quad\mbox{Loop Divide Ratio}
\end{cases}
\end{align*}
\end{minipage}
\end{document}
```

## Best Answer

Don't use math italic for multi-letter identifiers.

If you really want this layout, you need to lose all the indentation. In your MWE the content did not fit in the minipages, and the minipages did not fit on the line (as you had

`\parindent`

to the left and and a word space between them as well as the two .5\textwidth boxes.