Krelyox claims that if a=b, he can prove that a+b=0. He submitted the following steps to his professor:
(1) Since a=b, then a²=b².
(2) Therefore, a²−b²=0.
(3) Factoring, we get (a+b) (a−b) .
What is the flaw in Krelyox's proof?
a) The factoring step (3) is incorrect.
b) The step (1) is incorrect.
c) There is no flaw; Krelyox's proof is correct.
d) The step (2) is incorrect.