document.write( "Question 524819: A plane flies 600 miles against a steady 25mph headwind and then returns to the same point with the wind. If the trip takes 10 hours what is the planes speed while still in the air? \n" ); document.write( "
Algebra.Com's Answer #347949 by mananth(16946)\"\" \"About 
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plane speed x mph
\n" ); document.write( "wind speed 25 mph
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\n" ); document.write( "Distance with wind 600 miles
\n" ); document.write( "Distance against wind 600 miles
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\n" ); document.write( "spee with wind x + 25 mph
\n" ); document.write( "speed against x -25 mph
\n" ); document.write( "Total time = 9 hours
\n" ); document.write( "Time with current= 600 /( x + 25 )
\n" ); document.write( "time against current 600 / ( x -25 )
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\n" ); document.write( "Time with current + time against = 10 hours
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\n" ); document.write( "600 /( x + 25 ) + 600 /(x -25 ) = 10
\n" ); document.write( "LCD = ( x + 25 )* (x -25 )
\n" ); document.write( "multiply the equation by the LCD
\n" ); document.write( "we get
\n" ); document.write( "600*(x-25)+600(x+25)=10(x^2-625 )
\n" ); document.write( "600x-15000+600x+15000=10X^2-6250
\n" ); document.write( "1200x=10x^2-6250
\n" ); document.write( "10X^2-1200x-6250=0
\n" ); document.write( "10x^2-1200x-6250=0
\n" ); document.write( "/ 10
\n" ); document.write( "x^2 -120 x -625 = 0\r
\n" ); document.write( "\n" ); document.write( "x^2-125x+5x-625=0
\n" ); document.write( "x(x-125)+5(x-125)=0
\n" ); document.write( "(x+5)(x-125)=0
\n" ); document.write( "x= 125 speed of plane
\n" ); document.write( "negative is ignored. speed cant be negative
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