document.write( "Question 447686: An airplane flies 320 miles with the wind and 280 miles against it in the same length of time. If the speed of the wind is 30 mph, what is the speed of the airplane in still air? \n" ); document.write( "
Algebra.Com's Answer #308150 by jorel1380(3719)\"\" \"About 
You can put this solution on YOUR website!
320/x+30=280/x-30
\n" ); document.write( "280x+8400=320x-9600
\n" ); document.write( "40x=18000
\n" ); document.write( "x=450 mph..
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