An airplane's position changes -1500 feet per minute. What integer represents the total change in position of the airplane after 5 minutes?

Question

Am I suppose to multiply or divide? That is what I dont understand. 

Answer 1

The units for rate of change are given as "feet per minute"  (that is,  ft/min )

The units for elapsed time are given as "minutes"

 

When you multiply (ft/min)*(min), the minutes cancel, leaving only feet.

 

At a rate of change of (-1500 ft/min), 5 min later, the plane's position is:

     (-1500 ft/min)*(5 min) = -7500 ft      [that is, 7500 ft lower than before]