Yes. You're rigth.
There are many ways of solving such an equation.
So it would also be great to have an interactive tool to follow up the semplification.
Furthermore sometimes we just see the most elegant way to perform semplification.
I do not expect me from a programming language to "Just See" the correct way.
Getting philosophical now ????

However putting together a little bit of what I understood:
-- first we have to parse the formula
-- then we have to project the formula onto an internal representation ( a tree with single objects representing the numbers, maybe one object holding the fraction ? )
-- present this graphically shouldn't be so difficult.
-- Ask the user how to proceed further
-- present the result of the semplification choosed by the user
-- ask again the user for the next step
present .......
-- and so on

cheers reinhard