Pleasee help, im super confused

An airport in death valley is 60 feet below sea level, and an airplane is flying 2,000 feet above sea level. how many feet must the plane descend in order to land? a. 2060 b. 2000 feet c. 1940 feet d. 1880 feet e.1400 feet will mark as brainliest

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)