Thefollowingiswhatseemstobeamathematicalproofthattwoequalsone.What'swrongwithit?a=baa=abaa-bb=ab-bb(a+b)(a-b)=b(a-b)a+b=ba+a=a2a=a2=1

Question

The following is what seems to be a mathematical proof that two equals one.What's wrong with it?
a = b aa = ab aa -bb = ab - bb (a + b)(a - b) = b(a - b) a + b = b a + a = a 2a = a 2 = 1

Answer 1

a = b aa = ab (here, you must prove a isn't equal to 0,so the rest of them don't make sense any more) aa -bb = ab - bb (a + b)(a - b) = b(a - b) a + b = b a + a = a 2a = a 2 = 1
get it?
hopefully it helps you~