Hello from MrBillDoesMath!
I think more info is needed but here's a first step.
Suppose
4y + 3= 3y + x
Subtracting 3y from each side gives
4y - 3y + 3 = (3y - 3y) + x or
y + 3 = x.
Subtracting 3 from both sides gives:
y = x - 3.
So.... if you have another equation involving x and y you could substitute the above y value (i.e. x-3) for every occurrence of y
Regards, MrB
