Looking for critique on my code

[nilamo]

        if(a==0):
            print("\nThe \"A\" coefficient can't be equal to zero.\n")
        if((a==0)&(CanCalc==False)):
            print("and")
        if(CanCalc==False):
            print("\nYou can't enter letters.\n")

Why not...

        if(a==0):
           print("\nThe \"A\" coefficient can't be equal to zero.\n")
           if(CanCalc==False):
               print("and")
               print("\nYou can't enter letters.\n")

You've got a while loop, but no way to end the loop.  How do you stop the program?  ctrl+c?
You do a lot of bitwise comparisons... in python, the ideomatic way to do that is simply using the and keyword (so, if a==0 and not CanCalc: for example)