document.write( "Question 474949: Hi, please help me with this:\r
\n" ); document.write( "\n" ); document.write( "When an airplane flies with a given wind, it can travel 3,000 kilometer in 5 hours. When the same airplane flies in the opposite directions against the wind, it takes 10 hours to fly the same distance. Find the speed of the plane in still air and the speed of the wind.
\n" ); document.write( "Hint: let x = be the speed of the wind still air y = the speed of the wind \n" ); document.write( "
Algebra.Com's Answer #325701 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
Distance = same= 3000
\n" ); document.write( "plane speed =x
\n" ); document.write( "wind speed =y
\n" ); document.write( "t=d/r
\n" ); document.write( "3000 / ( x - y )= 10.00
\n" ); document.write( "10 ( x - y ) = 3,000.00
\n" ); document.write( "10 x -10 y = 3000 ....................1
\n" ); document.write( "3000 / ( x + y )= 5.00
\n" ); document.write( "5.00 ( x + y ) = 3000
\n" ); document.write( "5.00 x + 5.00 y = 3000 ...............2
\n" ); document.write( "Multiply (1) by 1.00
\n" ); document.write( "Multiply (2) by 2.00
\n" ); document.write( "we get
\n" ); document.write( "10 x + -10 y = 3000
\n" ); document.write( "10 x + 10 y = 6000
\n" ); document.write( "20 x = 9000
\n" ); document.write( "/ 20
\n" ); document.write( "x = 450 mph plane speed
\n" ); document.write( "
\n" ); document.write( "plug value of x in (1)
\n" ); document.write( "10 x -10 y = 3000
\n" ); document.write( "4500 -10 y = 3000
\n" ); document.write( "-10 y = 3000 -4500
\n" ); document.write( "-10 y = -1500
\n" ); document.write( " y = 150 mph wind speed
\n" ); document.write( " \n" ); document.write( "
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