Subject: How do matter and antimatter interact mathematically?

At elementary level we understand that if we add a number squared to its 
negative number squared what we get is twice the square of the number.
Now let's apply this concept to a world of matter, antimatter and one which has 
both.

Suppose we have an amount of matter A and an amount of antimatter -A, we add 
them what we get is zero. suppose we sqare them then what happens the 
antimatter world falls into the matter world ( converse is not true for matter 
world) and we get a summation as twice the sqaure of matter and 
resultantly ...???

Should not the dealings solely with -ve numbers fall in the third quadrant and 
tose with +ve numbers in first quadrant and therefore diffrent altogather.

Re: How do matter and antimatter interact mathematically?