Where is the mistake in these mathematical equations?
x = 2
x(x-1) = 2(x-1)
x2-x = 2x-2
x2-2x = x-2
x(x-2) = x-2
x = 1

The equation is solved the right way, apart from one little detail. There must be stated
that x does not equal y, because there would be dividing by zero, which is not defined in
maths.