document.write( "Question 869585: An airplane is with the wind can cover 500 miles in 2 hours. the return trip against the wind cover 2.5 hours. what is the speed of the plane? what is the speed of the air?
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Algebra.Com's Answer #524296 by lwsshak3(11628)\"\" \"About 
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An airplane is with the wind can cover 500 miles in 2 hours. the return trip against the wind cover 2.5 hours. what is the speed of the plane? what is the speed of the air?
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\n" ); document.write( "let x=speed of plane in still air
\n" ); document.write( "let c=speed of the wind
\n" ); document.write( "x+c=speed of plane with the wind
\n" ); document.write( "x-c=speed of plane against the wind
\n" ); document.write( "travel time*speed=distance
\n" ); document.write( "...
\n" ); document.write( "2(x+c)=500
\n" ); document.write( "2.5(x-c)=500
\n" ); document.write( "..
\n" ); document.write( "2x+2c=500
\n" ); document.write( "2.5x-2.5c=500
\n" ); document.write( "..
\n" ); document.write( "5x+5c=1250 (mult 1st eq by 2.5)
\n" ); document.write( "5x-5c=1000 (mult 2nd eq by 2.0)
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\n" ); document.write( "10x=2250
\n" ); document.write( "x=225
\n" ); document.write( "2c=500-2x=500-450=50
\n" ); document.write( "c=25
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\n" ); document.write( "speed of plane in still air=225 mph
\n" ); document.write( "speed of the wind=25 mph \n" ); document.write( "
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