Below we prove that 2 = 1:

Suppose that x = y. Then holds:

2x - x = 2y - y

This we can rewrite to:

2x - 2y = x - y

This we can rewrite to:

2 (x - y) = x - y

If we now divide by x - y, we get:

2 = 1

The question: Where is the fault in this proof?

The answer: Click here!