2 is equal to 1?

Let's check:

Let a and b be real, where a and b are nonzero. Suppose a = b.

So if a = b, multiplying both sides of equality by The we have:

The²= ab

Subtracting B² on both sides of equality we have:

The²-B²= ab-b²

We know (factorization) that The²-B²= (a + b) (a-b). Soon:

(a + b) (a-b) = ab-b²

Putting B in evidence on the right side we have:

(a + b) (a-b) = b (a-b)

Dividing both sides by (a-b) we have:

a + b = b

As at the beginning we said that a = bso instead of The I can put B:

b + b = b

Therefore 2b = b. Dividing both sides by B we finally came to the conclusion:

2=1

Obviously this demonstration has an error because we all know that 2 is not equal to 1 (or does anyone have any questions?). Click below to find out what the error is:

In this demonstration comes a stage where we have:
(a + b) (a-b) = b (a-b)

According to the demonstration, the next step would be:

We divided both sides by (a-b).

There is the mistake !!!

At first we assume a = b, so we have to a-b = 0.

Division by zero does not exist !!!