Find the mistake

Question

Find the mistake

anonymous · Answer

$$a=b$$
$$a^2=ab$$
$$a^2-b^2=ab-b^2$$
$$(a-b)(a+b)=b(a-b)$$
$$a+b=b$$
$$2b=b$$
$$2=1$$

anonymous · Answer

@mathslover @Carniel @Compassionate

anonymous · Answer

unkle if you've seen this one you can't comment =P

unklerhaukus · Answer

dividing by zero is not allowed

anonymous · Answer

darn -.-

mathslover · Answer

it is mathematic fallacy

anonymous · Answer

the last line... 2=1

anonymous · Answer

the last line is correct divide by b on both sides

unklerhaukus · Answer

$(a-b)=0$

anonymous · Answer

1=2 ?

anonymous · Answer

Unkle ruined it lol dpaln would have just been chilling here lol

anonymous · Answer

the last line is corect for the line above

anonymous · Answer

yeh, u divided by(a-b) which is zero, nd tht is nt allowed

carniel · Answer

How does 2b = b. 1 cant = 2

anonymous · Answer

why can't u divide by zero?

anonymous · Answer

I need tougher ones than this one... too many smart people lol

compassionate · Answer

The third step is incorrect. $$a^2 - b^2 $$
Moreover, $$a^2 - b^2 = ab - ab$$

anonymous · Answer

that's the whole point the error is above that

anonymous · Answer

the third step is correct, it's just subracting b^2 on both sides

carniel · Answer

Its line 3 bro :|

compassionate · Answer

That doesn't make any sense. The whole purpose is to remain in constant equality.

carniel · Answer

ts line 5 :0 A = B cant be A+B=B

compassionate · Answer

To my logical fallacies.

anonymous · Answer

yes and if you subtract b^2 from both sides the equation is stll equal. Unkle had the right answer

line 4: if a=b  (a-b)=0 and in line 4 you're dividing by a-b

anonymous · Answer

in other words you're dividing by zero

unklerhaukus · Answer

sorry for ruining  it

carniel · Answer

Thats the 1st error :O From there its more cuz of that

anonymous · Answer

@UnkleRhaukus  i'll just need a harder one next time