Most of the time (at least at my high school student level), we are using variables such as *a*, *b* or $\theta$, and functions such as *f, g* etc... 

But would it be possible to use multiple characters ? For example to use *triple(x) = 3x* instead of *f(x) = 2x* ?  

In my opinion it would enable some things to be much more clear in many situations, here is another example :
$$area = width \times height$$
Instead of $a = w \times h$, where you would need to go back in the text to find wha a, w and h are for.