Is there a VBA code to simplify (linear) algebraic expressions? (using text input)

As an example here's an input and desired output string:

I:           y+y-2(3-x)-0.5x-2.1
O:           2y+1.5x-8.1

This type of problem can be probably done easily using matrices. However it would take quite a while to actually make the code and I think someone probably have made such code already because this is quite a general problem. I think a large part of the problem would be simply to convert the text to matrices.

Notes: In case existing programs don't deal with implicit multiplication or need the input to be in a slightly different format, I could just sort that out myself.

I know that some software exists to solve these type of problems, but I can't find an easy way for excel and other software to communicate.