discrimination against negative numbers?

The negative numbers have formed a union and have been protesting for equal representation. They won some ground and that's why Wall Street had such a huge loss last year. Some believe that we should now end affirmative action for negative numbers since they have no problem getting themselves into top statistics (i.e. unemployment, federal defecit, public school performance, etc.).

We can algebraically prove that the product of two negatives is a positive, but you first have to understand what a negative actually is. Given any positive real number x, we define -x to be the unique real number such that x + (-x) = 0. That is, it is the additive inverse of x. So, let a and b be positive real numbers. Then,

0 = -a(0) = -a(b + (-b)) = -ab + (-a)(-b)

Shortening that down, we have 0 = -ab + (-a)(-b). To get rid of the -ab on the right, we add ab to both sides, which gives you ab = (-a)(-b), which is what we were trying to prove.

remember that 2x2 means 2+2 " two times " =4 , and 3x5 means 3+3+3+3+3 " five times " = 15

thus : -3x5 means (-3)+(-3)+(-3)+(-3)+(-3) " five times = -15

so : -1x5 = 5x-1 = -5

thus : (-3)x(-5) = [ (-3)x(5) ] x (-1) = -15 x -1 = 15

hence : -2x-2 = 4 and not (-4)