Validating Math Expressions

Question

Hi all

I have an interesting scenario. But very confused on how to implement. Here is what it is:

I need to design an online system which evaluates the right answer for a mathematical question. For example I have a question for which the answer needs to be (X²+2XY+3)/ (XYZ+9). Now there might be other possible answers as well for each question , as for the above the other answer might be (X²+2YX+3)/ (XYZ+9) and the other might be (X²+2YX+3)/ (ZXY+9). 

My case is I have to evaluate the user input which I need to compare with the right possible answers..In case any one of the possible answers matches with the user input then mark it as 'Right' answer. matches in the sense NOT THE VALUE OF THE EXPRESSION but the EXPRESSION BY ITSELF. How to compare these kind of Math algebraic expressions using C#.

Please help with your sample coding.

Your ideas and time will be much appreciated.

Thanks in advance

Anil