1: Take the equation a = b

2: Now multiply both side of the equation by a, giving:

a2 = ab

3: Add a2 - 2ab to each side, which gives:

a2 + a2 - 2ab = ab + a2 - 2ab

4: Simplify that equation:

2(a2 - ab) = a2 -ab

5: Divide both sides by (a2 - ab), which, astonishingly gives:

2 = 1