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