How to distribute narrow expressions along a line?

Question

I want something like this:

two narrow equations/words equally distributed along the linewidth. I used next code:

\documentclass{beamer}
\usetheme{Warsaw}
\begin{document}
\begin{frame}
\begin{block}{My block}
\hfill$a+a=a$\hfill$a\cdot a=a$\hfill\phantom{.}
\end{block}
\end{frame}
\end{document}

As you can see I've used a \phantom{.} to force end of line \hfill. My question is do you know a better solution? Probably Werner's answer in Standard math environment for equally-spaced columns of expressions? is a better way to do it, but I think it's to much code.

Answer 1

TeX removes a glue item at the end of a paragraph, so

\hfill$a+a=a$\hfill$a\cdot a=a$\hfill

doesn't work. You have to use space that doesn't disappear:

\hspace*{\fill}$a+a=a$\hfill$a\cdot a=a$\hspace*{\fill}

(The one at the start might be \hfill, but it's good practice to use \hspace* when one really wants space at the beginning and at the end of a line).