Hello, I am having trouble with this problem:
Find the product of (x+y-2) and (x+y+2)
Now, obviously I can use the, so to speak, "old fashion" way by foiling it. But they say in the solution that I can use a special product and rewrite it as:
[(x+y)-2][(x+y)+2]
And furthermore be written as:
(x+y)^2-2^2
Could someone please explain how they are doing this?
Thank you very much.