BE PREPARED TO BE SHOCKED (2 = 1)

Let a and b represent two equal quantities which are not zero
a = b

Multiplying by a
a² = ab

Substract b²
a² – b² = ab – b²

Finding out factors
(a + b)(a - b) = b(a - b)

Dividing by (a - b)
a + b = b        

Since we know a = b
b + b = b
2b = b
Which finally gives
2 = 1                 ;)