Serena parachutes from a plane at a height of 20,000 ft above sea level. several minutes later she lands on the ground 15 ft below sea level . what was the total vertical distance that serena parachuted?
explain : )

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.