document.write( "Question 65311: The speed of an airplane in still air is 214mph. The plane travels 819mi against the wind and 1505 mi with the wind in a total time of 12 hrs. what is the speed of the wind? \n" ); document.write( "
Algebra.Com's Answer #45875 by stanbon(75887)\"\" \"About 
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The speed of an airplane in still air is 214mph. The plane travels 819mi against the wind and 1505 mi with the wind in a total time of 12 hrs. what is the speed of the wind
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\n" ); document.write( "Let \"w\" be the speed of the wind.
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\n" ); document.write( "Against the wind DATA:
\n" ); document.write( "distance=819 miles ; Rate=(214-w); time= d/r=819/(214-w) hrs
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\n" ); document.write( "With the wind DATA:
\n" ); document.write( "distance=1505 miles ; rate=(214+w); time = d/r 1505/(214+w) hrs
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time + time = 12 hrs
\n" ); document.write( "819/(214-w) + 1505/(214+w) = 12
\n" ); document.write( "819(214+w) + 1505(214-w)= 12(214^2-w^2)
\n" ); document.write( "(2324)(214)+(819-1505)w = 12(45796)-12w^2
\n" ); document.write( "12w^2-686w-52216=0
\n" ); document.write( "6w^2-343w-26108=0
\n" ); document.write( "w=[343+-sqrt(343^2-4*6*-26108]/12
\n" ); document.write( "w=[1205.69]/12
\n" ); document.write( "w=100.47 mph (speed of the wind)
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
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