document.write( "Question 137231: the speed of the airplane in still air is 186mph. the plane travals 538 mi againt the wind and 1415 mi with the wind in a total time of 12 hr. what is the speed of the wind \n" ); document.write( "

Algebra.Com's Answer #100519 by checkley77(12844) $\"\"$ $\"About$

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538/(186-x)+1415/(186+x)=12
\n" ); document.write( "[538(186+x)+1415(186-x)]/(186-x)(186+x)=12 now cross multiply
\n" ); document.write( "12(186-x)(186+x)=538(186+x)+1415(186-x)
\n" ); document.write( "12(34,596-x^2)=100,068+538x+263,190-1415x
\n" ); document.write( "415,152-12x^2=363,258-877x
\n" ); document.write( "-12x^2-877x+415,152-363,258=0
\n" ); document.write( "-12x^2-877x+51,894=0
\n" ); document.write( "using the quadratic equation we get: $\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$
\n" ); document.write( "x=(877+-sqrt[-877^2-4*-12*51,894])/2*-12
\n" ); document.write( "x=(877+-sqrt[769,129+2,490,912])/-24
\n" ); document.write( "x=(877+-sqrt[3,260,041)/-24
\n" ); document.write( "x=(877+-1,805.5583)/-24
\n" ); document.write( "x=(877-1,805.5583)/-24
\n" ); document.write( "x=-928.5583/-24
\n" ); document.write( "x=38.69 mph is the speed of the wind.\r
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