Let a real number, let . We have and and of course , we will useequalities like , with . We have Thus But We deduce Or Or And Or And Or And And If we take and , it is absurd ! We dit not multiply or divide by zero !
We have Where is the mistake ? Numerically, there is perhaps one but not algebraically ! Ah ! You have put a 2 below, we have -2=-2=-2 !
I agree - the "2 below" in your original post is an error. But you also continue to include that "2 below" in subsequent steps. I think that is the source of your error.