If I have a numerical equation (i.e. no unknowns) in LaTeX, is it possible to have the equation typeset and evaluated in one go?

[![equation showing expanded and calculated forms](https://i.stack.imgur.com/ZpxA3.png)](https://i.stack.imgur.com/ZpxA3.png)

I know calculations can be done relatively easily by embedding Lua code using LuaTeX, but this requires re-writing the equation. A solution would also have to cope with very small and large numbers, so I believe this is outside the scope of normal TeX.

It just seems silly to define a formula in LaTeX and then have to write it again in a linear format in order to compute its value.

Thanks in advance.