Just for those who don't see the error: 2(a^2 - ab) = a^2 - ab On this line, a^2 - ab is 0 (look at line 2). You wind up dividing both sides by 0, thus resu

Just for those who don't see the error: 2(a^2 - ab) = a^2 - ab On this line, a^2 - ab is 0 (look at line 2). You wind up dividing both sides by 0, thus resulting in the false proof.