probibility and statistics?

Question

Here is probibility density function of X & Y (f(x,y)).What would be
f(x) and f(y):

f(x,y):
12/5(x+y) 0 0 otherwise

Answer 1

To find f(x) you must determine what y would be by default. If they defaulted to 0, the functions would be.

f(x) = 12/5(x) 0 f(y) = 12/5(y) 0

Answer 2

To find f(x), you have to integrate f(x,y) w.r.t. y from 0 to 1. Similar, for f(y) you integrate f(x,y) w.r.t. x from 0 to 1.