How to distribute narrow expressions along a line?

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.

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