Question 655390: a jet plane traveling at a constant speed goes 1200 miles with the wind, then turns around and travels for 1000 miles against the wind. If the speed of the wind is 50mph and the total flight took 4 hours, find the speed of the plane.
What is the equation to solve this word problem?
Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website! a jet plane traveling at a constant speed goes 1200 miles with the wind, then turns around and travels for 1000 miles against the wind. If the speed of the wind is 50mph and the total flight took 4 hours, find the speed of the plane.
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let x=speed of plane
x+50=speed of plane in with the wind
x-50=speed of plane in against the wind
travel time=distance/speed
..
1200/(x+50)+1000/(x-50)=4
LCD:(x+50)(x-50)
1200(x-50)+1000(x+50)=4(x+50)(x-50)
1200x-60000+1000x+50000=4(x^2-50^2)=4(x^2-2500)=4x^2-10000
2200x-10000=4x^2-10000
4x^2-2200x=0
x^2-550x=0
x(x-550)=0
x=550
speed of plane=550 mph
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