Answer:
A. -500
Explanation:
Find the slope using rise over run (change in y / change in x)
Find the change in the y values (height of the plane):
24,000 - 18,000
= 6,000
Find the change in the x values (miles from the airport)
(60 - 72)
= -12
Divide 6000 by -12:
6000/-12
= -500
So, the slope of the plane's path is A. -500