can you help me with this? thanks a lot!

1. Show that Cou(X + Y. Z) = Cov(X, Z) + Cov(Y. Z). 2. Suppose that Y ~ Uniform(0, 1) and X | Y = y ~ Uniform(y, 1). Find (a) the joint probability density function of X and Y and (b) the conditional probability density function of Y' given X = x. Reference: For any a, b E R, a Uniform(a, b) random variable has pdf f(x) = ba ocx