if x...y=(x-y)^2 for all integers which are the following must be true? 1)x...y=y...x 2)x....y=x...(-y) 3)x...(-y)=-x..y

#1 because

(x-y)^2 = (y-x)^2

why don't you try the others? Just remember that (z)^2 = (-z)^2