Answer:
12 minutes
Step-by-step explanation:
If the rate of the plane is -450 meters per minute, then you have to use the "division" operation in order to know how much time it takes for the plane to reach an altitude of -5,400 meters.
-5,400 meters ÷ -450 meters/minute = 12 minutes
It will take 12 minutes for the plane to reach an altitude of -5,400 meters.
Let's check:
-450 meters x 12 minutes = -5,400 meters
