document.write( "Question 143523: I need some help in trying to solve the following equation. I have been trying to solve it by using r+50 = 1200/t and r-50 = 1000/4-t but cant seem to get an answer that works back into the equation. \r
\n" ); document.write( "\n" ); document.write( "A jet traveling at a constant speed goes 1200km with the wind, then turns around and travels for 1000 km against the wint. If the speed of the wind is 50 km/h and the total flight took 4 hours, find the speed of the plane in still air.\r
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Algebra.Com's Answer #104450 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
A jet traveling at a constant speed goes 1200km with the wind, then turns around and travels for 1000 km against the wind. If the speed of the wind is 50 km/h and the total flight took 4 hours, find the speed of the plane in still air.
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\n" ); document.write( "Try doing it this way, write a time equation, Time = \"dist%2Frate\":
\n" ); document.write( "\"1200%2F%28%28r%2B50%29%29\" + \"1000%2F%28%28r-50%29%29\" = 4
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\n" ); document.write( "1200(r-50) + 1000(r+50) = 4(r-50)(r+50)
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\n" ); document.write( "1200r - 60000 + 1000r + 50000 = 4(r^2 - 2500)
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\n" ); document.write( "2200r - 10000 = 4r^2 - 10000
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\n" ); document.write( "0 = 4r^2 - 2200r - 10000 + 10000
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\n" ); document.write( "4r^2 - 2200r = 0
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\n" ); document.write( "4r(r - 550) = 0
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\n" ); document.write( "r = 550 km/hr speed in still air
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\n" ); document.write( "Check solution by finding the times of each trip
\n" ); document.write( "1200/(550+50) = 2 hr
\n" ); document.write( "1000/(550-50) = 2 hr
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