document.write( "Question 134375: when a plane flies into the wind, it can travl 3000 km in 6 hours. when it flies with the wind, it can travel the same distance in 5 hours. Find the rate of the plane in still air and the rate of the wind. \n" ); document.write( "
Algebra.Com's Answer #98301 by ankor@dixie-net.com(22740)\"\" \"About 
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when a plane flies into the wind, it can travel 3000 km in 6 hours. when it flies with the wind, it can travel the same distance in 5 hours. Find the rate of the plane in still air and the rate of the wind.
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\n" ); document.write( "Let s = speed of plane in still air
\n" ); document.write( "let w = speed of the wind
\n" ); document.write( "then
\n" ); document.write( "(s-w) = ground speed into the wind
\n" ); document.write( "and
\n" ); document.write( "(s+w) = ground speed with the wind
\n" ); document.write( ":
\n" ); document.write( "Write 2 distance equations: Dist = time * speed:
\n" ); document.write( "6(s-w) = 3000
\n" ); document.write( "5(s+w) = 3000
\n" ); document.write( ":
\n" ); document.write( "Simplify both equations; divide the 1st one by 6; the 2nd one by 5, you have:
\n" ); document.write( "s - w = 500
\n" ); document.write( "s + w = 600
\n" ); document.write( "--------------adding equations eliminates w, find s:
\n" ); document.write( "2s +0 = 1100
\n" ); document.write( "s = 1100/2
\n" ); document.write( "s = 550 km/hr plane speed in still air
\n" ); document.write( ":
\n" ); document.write( "Find w using s + w = 600
\n" ); document.write( "550 + w = 600
\n" ); document.write( "w = 600-550
\n" ); document.write( "w = 50 km/hr is the speed of the wind
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solutions in the 1st original equation
\n" ); document.write( "6(550 - 50) = 3000; confirms our solution \n" ); document.write( "
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