Proof That 2=1

[katana]

Let us start by assuming that a=b
Multiplying both sides by a:
a²=ab
Subtracting b² from both sides:
a²-b²=ab-b²
Factorising both sides:
(a+b )(a-b )=b(a-b )
Dividing both sides by a-b:
(a+b )=b
But a=b, so, substituting a for b:
a+a=a
Divide both sides by a:
2=1
QED

[Swiss1960]

Not bad... took me almost a minute to find the mistake

[krisb]

1 plus 1 equals 2.

Much easier.

[kotsak]