I need detailed solutions.

Problem 1: [3, Exercise 3.75] Let X and Y be random variables having joint density function _ :r+y 0x$l,0$y51 f(:r,y) -{ 0 otherwise. Find (a) Var(X), (b) Var(Y), (C) (xx, ((1) cry, (e) axy, (f) p. Problem 2: [3, Exercise 3.76] Work Problem 1 if the joint density function is e'l'H") a: 2 0, y a 0 f(:r,'y) _ { 0 otherwise