document.write( "Question 24144: a light plane flew from its home base to an airport 255 miles away. with a headwind the trip took 1.7 hours the return trip with a tailwind took 1.5 hours. Find the average air speed of the plane and the average wind speed? \n" ); document.write( "
Algebra.Com's Answer #12839 by Paul(988)\"\" \"About 
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Let the speed of the plane be x
\n" ); document.write( "Let the speed of the wind be y\r
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\n" ); document.write( "\n" ); document.write( "1.7(x-y)=255 --->1.7x-1.7y=255 (equation 1)
\n" ); document.write( "1.5(x+y)=255 --->1.5x+1.5y=255 (equation 2)\r
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\n" ); document.write( "\n" ); document.write( "Multiply equation 1 by 15 and equation 2 by 17 to get:
\n" ); document.write( "25.5x-25.5y=3825 (add)
\n" ); document.write( "25.5x+25.5y=4335 (add)
\n" ); document.write( "----------------
\n" ); document.write( "51x=8160 (divide both sides by 51)
\n" ); document.write( "x=160\r
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\n" ); document.write( "\n" ); document.write( "Solve for y:
\n" ); document.write( "1.7(160)-1.7y=255
\n" ); document.write( "272-1.7y=255
\n" ); document.write( "-1.7y=--17
\n" ); document.write( "y=10\r
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\n" ); document.write( "\n" ); document.write( "Hence the speed of the plane is 160mi/h and the speed of the wind is 10mi/h.
\n" ); document.write( "Paul.
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