document.write( "Question 500983: An airplane takes 5 hours to travel a distance of 4400km against the wind. The return trip takes 4 hours with the wind. What is the rate of the plane in still air and what is the rate of the wind? \n" ); document.write( "

Algebra.Com's Answer #338369 by mananth(16946) $\"\"$ $\"About$

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Plane speed =x km/h
\n" ); document.write( "Wind speed =y km/h
\n" ); document.write( "against wind x-y 5.00 hours
\n" ); document.write( "with windx+y 4.00 hours
\n" ); document.write( "
\n" ); document.write( "Distance = same= 4400 miles
\n" ); document.write( "t=d/r
\n" ); document.write( "4400 / ( x - y )= 5.00
\n" ); document.write( "5 ( x - y ) = 4,400.00
\n" ); document.write( "5 x -5 y = 4400 ....................1
\n" ); document.write( "4400 / ( x + y )= 4.00
\n" ); document.write( "4.00 ( x + y ) = 4400
\n" ); document.write( "4.00 x + 4.00 y = 4400 ...............2
\n" ); document.write( "Multiply (1) by 4.00
\n" ); document.write( "Multiply (2) by 5.00
\n" ); document.write( "we get
\n" ); document.write( "20 x + -20 y = 17600
\n" ); document.write( "20 x + 20 y = 22000
\n" ); document.write( "40 x = 39600
\n" ); document.write( "/ 40
\n" ); document.write( "x = 990 km/h
\n" ); document.write( "
\n" ); document.write( "plug value of x in (1)
\n" ); document.write( "5 x -5 y = 4400
\n" ); document.write( "4950 -5 y = 4400
\n" ); document.write( "-5 y = 4400 -4950
\n" ); document.write( "-5 y = -550
\n" ); document.write( " y = 110 km/h
\n" ); document.write( " \n" ); document.write( "

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