Question

The altitude a (in feet) of a plane t minutes after liftoff is given by a=3400t+600. How many minutes after liftoff is the plane at an altitude of 21,000 feet?

Answer 1

21,000-600 = 20,400
20,400/3400 = 6
t = 6

21,000=3,400(6)+600
21,000=20,400+600
21,000=21,000


34.00
*6
__
204.00

3,400*6=20,400