Add equations to text

Question

I've got a really simple question. I'd like to write a mathematical proof in LaTeX, so my document will contain both text and formulae embedded in it. For example, I want to add this to it:

How can I write this efficiently, without putting the entire text into an \mbox{} element?

Answer 1

Only wrap the equations in $...$, you can enter and leave math mode all throughout the document.

This page shows examples with formulas both inline in a paragraph and on their own lines.

Answer 2

If most of the content is math mode, the use \text{} to imbed text within equations.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\text{Let } D \subseteq \mathbf{R}, D \ne 0
\]

or in inline mode: $\text{Let } D \subseteq \mathbf{R}, D \ne 0$
\end{document}