Let a=b.
Then a^2=ab
a^2 - b^2 = ab - b
(a+b)(a-b)=b(a-b)
a+b=b
Since a=b
then 2b=b
2=1 ???
Where's the mistake???
2007-01-19 17:47:09 · 10 answers · asked by Master Chief 2 in Science & Mathematics ➔ Mathematics
Since a-b =0. you have not the right to divide by zero.
2007-01-19 17:58:02 · answer #1 · answered by maussy 7 · 0⤊ 0⤋
This so-called proof that 1 = 2 is so old that it was written on the back of the tablets of the Ten Commandments !!! LOL
To get from the 4th equation to the 5th equation, it is necessary to divide by (a-b). But it is a "given" that a = b. Therefore, a-b=0 and everyone knows that division by zero creates a mathematical fallacy.
2007-01-19 18:01:21 · answer #2 · answered by Anonymous · 0⤊ 0⤋
You did something impossible in the fourth step.
I assume you knew you did this, which means it is not a real question, just trying to stump us with a fake, trick sort of question, and that is not what this place is for.
If a=b, then a-b is zero, and in the fourth step you divided BOTH SIDES by ZERO which you CAN NOT DO.
What a pointless exercise.
2007-01-19 18:37:18 · answer #3 · answered by Anonymous · 0⤊ 0⤋
a^2 - b^2 = ab - b is wrong, should be
a^2 - b^2 = ab - b^2 (subtracting the same value from both sides)
2007-01-19 18:03:09 · answer #4 · answered by Robert M 2 · 0⤊ 0⤋
In the third line ,you have made it 0=0 and then in the next line you have factored 0 into (a+b)X0.This is not allowed
2007-01-19 18:10:58 · answer #5 · answered by alpha 7 · 0⤊ 0⤋
a^2 - b^2 = ab - b
(a+b)(a-b)=b(a-b)
ab-b does not factor to b(a-b) but to b(a-1)...
2007-01-19 18:05:51 · answer #6 · answered by ThisIsntMe 3 · 0⤊ 0⤋
the answer is that 1=1 in turn a=b
2007-01-19 17:57:57 · answer #7 · answered by Elizabeth M 2 · 0⤊ 0⤋
3rd row rh hand side b^2 or ab is missing
2007-01-19 17:58:41 · answer #8 · answered by Anonymous · 0⤊ 0⤋
a^2-b^2=ab-b^2
you missed a squared i think.
2007-01-19 17:55:35 · answer #9 · answered by Lucky 2 · 0⤊ 0⤋
no idea
2007-01-19 17:57:23 · answer #10 · answered by Anonymous · 0⤊ 0⤋