Let's assume
height of plane in feet =h
time in minutes =t
we are given
A plane is descending into the airport. After 5 minutes it is at a height of 6500 feet
so, we get one point as (5,6500)
After 7 minutes it is at a height of 5900 feet
so, we get another point as (7,5900)
we can use point slope form of line
points as
(5,6500)
x1=5, y1=6500
(7,5900)
x2=7 , y2=5900
Calculation of slope(m):
now, we can plug values
Equation of line:
we can use formula
we can plug values
Time of landing:
we can set h=0
and then we can solve for t
..............Answer