Dos es igual a uno

Is 2 = 1 ?

An impossible equation. or not?
If a = 1 and b = 1 then a = b .
Multiplying both sides of the equation for b , we have :
ab = b2
Subtracting both sides of the equality a2 are:
ab - a2 = b2 - a2
factoring :
to ( b - a) = (a + b ) ( b - a)
And simplifying the term ( b - a) :
a = a + b
Since a = b , then the expression is equivalent to :
a = a + a
Thus:
a = the 2nd
So:
1 = 2

 

Is correct this show ?