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You can put this solution on YOUR website!
\"Traveling for 4 hours into a steady head wind, a plane flies 1200 miles. The plane can make the return trip, flying with the wind, in 3 hours. Find the speed of the plane and the speed of the wind.
\n" ); document.write( "Show :
\n" ); document.write( "1) Define two variables
\n" ); document.write( "2) Write a system of equations
\n" ); document.write( "3) Solve the system of equations
\n" ); document.write( "4) Answer the question\"
\n" ); document.write( "..
\n" ); document.write( "1)
\n" ); document.write( "let x=speed of plane
\n" ); document.write( "let w=speed of wind
\n" ); document.write( "(x+w)=Speed of plane with wind
\n" ); document.write( "(x-w)=Speed of plane against wind
\n" ); document.write( "2)
\n" ); document.write( "Travel time=distance/speed
\n" ); document.write( "1200/(x+w)=3
\n" ); document.write( "1200/(x-w)=4
\n" ); document.write( "3)
\n" ); document.write( "3x+3w=1200
\n" ); document.write( "4x-4w=1200
\n" ); document.write( "..
\n" ); document.write( "3)
\n" ); document.write( "12x+12w=4800 (multiply by 4)
\n" ); document.write( "12x-12w=3600 (multiply by 3)
\n" ); document.write( "24x=8400
\n" ); document.write( "x=350
\n" ); document.write( "12w=4800-12*350
\n" ); document.write( "12w=60
\n" ); document.write( "w=5
\n" ); document.write( "..
\n" ); document.write( "4)
\n" ); document.write( "answers:
\n" ); document.write( "speed of plane=350 mph
\n" ); document.write( "windspeed=5 mph \n" ); document.write( "