Exercise # 2

Discover the error by logic (but all phormula are correct , believe me !!).

Let's write this                          a=a (right ?!)

Now, write this                         a*a=a*a (right?!)

Now, this                                   (a*a)-(a*a )=(a*a)-(a*a) (right!?)

Now, let's write the same

thing in a different matter    a*(a-a)=(a+a)*(a-a) (right?!)

Well, now let's simplify taking off

same element from right and left of sign =

We'll obtain                                 a=a+a

Or                                                a=2a

C'et a dir                                     1=2 (??)

Well, I assure you that all phormula applications are right, no trick, but for an elementar mistake..

Which one ??

We'll see later for the solution...

Claudio