Answers
19,600 feet
17,200 feet
14,800 feet
12,400 feet
Step-by-step explanation
The expression 22,000+(−480t) represent the height reached by the airplane at a given time t.
# when t = 5 minutes
22,000+(−480×5) = 22,000 - 2,400
= 19,600 feet
# when t = 10 minutes
22,000+(−480×10) = 22,000 - 4,800
= 17,200 feet
# when t = 15 minutes
22,000+(−480×15) = 22,000 - 7,200
=14,800 feet
# when t = 20 minutes
22,000+(−480×20) = 22,000 - 9,600
= 12,400 feet