You’re working with two random variables x and y , which may be dependent and for which v (x) = v (y ). show that the random variables w = (x+y ) and z = (x−y ) are uncorrelated. hint: nothing fancy — just simplify the covariance of w and z, using properties of covariance.

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.

The answer to your question is 25hope this !