# Precalculus 11

Hello,

An airplane makes a 990 km flight with a tailwind & returns, flying into the same wind. The total flying time is 3 hrs 20 mins & the airplanes speed in still air is 600 km/hr what is the the speed of the wind?

I'm as far as (990/(600-x))+(990/600+x))=10/3

but I can't figure out how to go from there!

Thanks a bunch :)
Kayla

1. same distance, there and back
v1*t1=v2*t2=990km
t1=3 1/3 hr -t2

v1=600+w
v2=600-w

(600+w)t1=990 or
t1=990/(600+w)
10/3-t1=990/(600-w)

10/3-990/(600+w) = 990/(600-w) so your equation is correct.

now, multipy each side by (600-w)(600+w)/990

10(600^2-w^2)/(3*990) = 600+w+600-w)
check that. Now is simplifies considerably, gather terms, and you have a quadratic equation. use the quadratic formula.

posted by bobpursley
2. multiply by the LCD

[990 (600 + x)] + [990 (600 - x)] = 10/3 (600 - x)(600 + x)

1188000 = 10/3 (360000 - x^2) ... 356400 = 360000 - x^2

x^2 = 3600

posted by scott

## Similar Questions

1. ### Math

Have you ever been on an airplane and heard the pilot say that the plane would be a little late because it would be flying into a strong headwind or that even though the plane was taking off a bit late, you would be making up time
2. ### Algebra

A pilot flew a 400-mile flight in 2.5 hours flying into the wind. Flying the same rate and with the same wind speed, the return trip took only 2 hours, with a tailwind. What was the speed of the wind?
3. ### math

If you are flying to a city 800 miles away, what will be the difference in flight times between flying into a 40-mph headwind and flying with a 40-mph tailwind if the plane's maximum speed with no wind is 160 mph?
4. ### math

If you are flying to a city 800 miles away, what will be the difference in flight times between flying into a 40-mph headwind and flying with a 40-mph tailwind if the plane's maximum speed with no wind is 160 mph?
5. ### Math

If you are flying to a city 400 miles away, what will be the difference in flight times between flying into a 40-mph headwind and flying with a 40-mph tailwind if the plane's maximum speed with no wind is 160 mph?
6. ### math

a small plane flying into the wind takes 3 hrs 20 min to complete a flight of 960 km. Flying with the wind the same plane takes 2 h 30 min to make the trip.what is the speed of the plane? what is the speed of the wind? can u plz
7. ### Algebra

Flying with wind, a plane flew 800 miles in 5 hrs. Flying against the wind, the plane flew the same distance in 8 hrs. Find the still air speed and wind speed.