Help me 5⋅f(1)+5⋅g(9)

Bugs bunny was 33 meters below ground, digging his way toward pismo beach, when he realized he wanted to be above ground. he turned and dug through the dirt diagonally for 80 meters until he was above ground

If p(a) = 0.70 and p(b) = 0.20, then a and b are independent events if

3x = 729 solve for x plz . it's urgent. will mark