document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=70489>Question 70489</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An airplane took 2.5 hours to fly 625 miles with the wind.  It took 4 hours and 10 minutes to make the return trip, against the same wind.  Find the wind speed and the speed of the plane in still air.  \r<BR>\n" );
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document.write( "Against a head wind, Jeff computes his flight time for a trip of 2,900 miles at 5 hours.  The flight would take 4 hours and 50 minutes if the head wind was half as much.  Find the head wind and the planes air speed.\r<BR>\n" );
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document.write( "In 1927 Charles Lindburg flew the Spirit of St. Louis from NYC to Paris at an average speed of 107.4mi/h.  11 years later, Howard Hughes flew the same route, averaged 217.1 mil/h, and took 16 hours and 57 minutes less time.  Find the length of their route.\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #50266 by </B><A HREF=/tutors/aboutme.mpl?userid=piglet162431><B>piglet162431(90)</B></A><img src=\"/images/stars/stars-08.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=piglet162431><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=50266\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let statements:<BR>\n" );
document.write( "let x be the be speed of the plane in still air.<BR>\n" );
document.write( "Let y be the speed of the wind.<BR>\n" );
document.write( "since d=rt, we can come upwith a system of equations. <BR>\n" );
document.write( "625=2.5(x+y)<BR>\n" );
document.write( "625=4 1/6(x-y)<BR>\n" );
document.write( "The first equation could be simplied into 250=x+y.<BR>\n" );
document.write( "the second equation, multiply both sides to the reciprocal of 4 1/6, which is 6/25:<BR>\n" );
document.write( "150=x-y<BR>\n" );
document.write( "now, line them up, and use addition method.<BR>\n" );
document.write( "x-y=150<BR>\n" );
document.write( "x+y=250<BR>\n" );
document.write( "2x=400<BR>\n" );
document.write( "x=200<BR>\n" );
document.write( "Plug this value back for y. 200-y=150, y=50. <BR>\n" );
document.write( "The speed of the plane in still is 200 m/h, whhile the speed of the wind is 50 m/h.<BR>\n" );
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