Someone answer this pick the right answer

Abouncy ball is dropped such that the height of its first bounce is 5.5 feet and each successive bounce is 64% of the previous bounce's height. what would be the height of the 7th bounce of the ball? round to the nearest tenth (if necessary).

If c(x) = 4x – 2 and d(x) = x2 + 5x, what is (cxd)(x)

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)