Solve both questions hand written and show work

3. Suppose the joint PDF of two RVs X and Y are given below. fx. x ( x, y ) = { c ( xy ' + x? y), if 0 s x s 1,0 sys1, 0, otherwise. (1) Find the value of c. (10 points) (2) Find the marginal PDFs of X and Y. (10 points) (3) Find E [X] and var (X). (15 points) 4. The joint OF of X and Y is given by fx,x ( x, y ) = 7 (x2 + 7). 0 Y) (10 points)