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Question 514713: I would appreciate some help, thanks so much! This is due tomorrow and I have no idea what to do!
Two planes leave LA at the same time. One heads to San Diego, the other to San Francisco. The San Francisco plane flies 50mph faster. In 1/2 hr, the planes are 275 miles apart. What are their speeds?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Two planes leave LA at the same time. One heads to San Diego, the other to San Francisco. The San Francisco plane flies 50mph faster. In 1/2 hr, the planes are 275 miles apart. What are their speeds?
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To San Diego DATA:
time = 1/2 hr ; rate = r mph ; distance = t*r = (r/2) miles
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To San Fran DATA:
time = 1/2 hr ; rate = r+50 mph ; distance = t*r = (1/2)(r+50) miles
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Equation:
dist + dist = 275 miles
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(r/2) + (r+50)/2 = 275
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Multiply thru by 2 to get:
r + r+50 = 550
2r = 500
r = 250 mph (speed of the plane to San Diego)
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r + 50 mph (speed of the plane to San Fran)
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Cheers,
Stan H.
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