Given:

**a=b**. Applying some basic identity transformations, we get:

a=b
a^2-ab=a^2-b^2
a(a-b)=(a+b)(a-b)
a=a+b
a=a+a
a=2a
1=2

With such a proof, we can show that
1=2, pi=E, 10000000000000=1, etc.... Can you spot the flaw?

(In reply to

A flawed proof? ( Solution ) by Ravi Raja)

Yep, I agree with Ravi's solution. Also the 6th step has a flaw in dividing the equaltion by "a". when a = 2a, a=0. You cannot divide anything by zero so that step is wrong too (Although when step 3 is wrong, according to Ravi, it doesn't matter what comes next)