Please help me with a detailed explanation :)

2. Find the marginal distributions (i.e., the distribution of X by itself and the distribution of Y by itself). (I) Let T be the triangular region in the x-y (II) The joint pmf is given by this table: plane whose vertices are at (0,0), (1,0), and (0, 1). The joint pdf is X 1 2 3 Y 2 if (x, y) ET 18 f(x, y) = COIN col WIH OI N 0 elsewhere