Is that a question or answer? If it's a question that's the right answer.
The answer is (x-y)^2
hope it helps!!!!!!
the formula is
(a-b)^2
and when you expand it, it becomes
a^2-2ab+b^2
Four tenths is expressed as .4
five thousandths is expressed as .005
the sum of these is .405 and divided by 2 (there are two numbers we added), we get .2025, that is the average