SOLUTION: A plane can travel 975 miles with a 40 mph tailwind in the same time it can travel 800 miles with a 30 mph headwind. How fast an the plane travel with no wind resistance?

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Question 729295: A plane can travel 975 miles with a 40 mph tailwind in the same time it can travel 800 miles with a 30 mph headwind. How fast an the plane travel with no wind resistance?
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
D=RT
975=(R+40)T
T=975/(R+40)
800=(R-30)T
T=800/(R-30)
THE TIMES ARE EQUAL SO:
975/(R+40)=800/(R-30)
975(R-30)=800(R+40)
975R-29,250=800R+32,000
975R-800R=32,000+29,250
175R=61,250
R=61,250/175
R=350 MPH. IN STILL AIR IS THE SPEED.
975=(350+40)T
975=390T
T=975/390
T=2.5 HOURS
PROOF:
800=(350-30)*2.5
800=320*2.5
800=800