let a=b

Then,

1. ab = a^2

2. ab - b^2 = a^2 - b^2

3. b(a - b) = (a + b)(a - b)

4. b = a + b

5. b = b + b

6. b = 2b

7. 1 = 2

which step is the flaw in the above proof?

• In 2nd step it is given, ab - b^2= a^2 - b^2
  As a=b, at this step result will be zero.
  So no further expansion or progression of equation is possible.
• 8 years agoHelpfull: Yes(0) No(0)