document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=299199>Question 299199</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An airplane took 4 hours to fly 1200 miles agianst a headwind.The return trip with the wind took 3 hours. Find the speed of the plane in still air and the speed of the wind. What is the speed of the wind in still air? What is the wind speed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #215082 by </B><A HREF=/tutors/aboutme.mpl?userid=MathTherapy><B>MathTherapy(10552)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathTherapy><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/cgi-bin/show-face.mpl?user=MathTherapy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=215082\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An airplane took 4 hours to fly 1200 miles agianst a headwind.The return trip with the wind took 3 hours. Find the speed of the plane in still air and the speed of the wind. What is the speed of the wind in still air? What is the wind speed?\r<BR>\n" );
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document.write( "Let the plane's speed be S, and the wind's speed W\r<BR>\n" );
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document.write( "Since it took 4 hours against a headwind to fly 1,200 miles, then speed = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1200%2F4 ALIGN=MIDDLE  ALT=\"1200%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > or 300 mph.\r<BR>\n" );
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document.write( "This means that the speed of the plane - windspeed = 300 mph, or, S - W = 300\r<BR>\n" );
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document.write( "Since it took 3 hours with the headwind to fly 1,200 miles, then speed = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1200%2F3 ALIGN=MIDDLE  ALT=\"1200%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > or 400 mph.\r<BR>\n" );
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document.write( "This means that the speed of the plane + windspeed = 400 mph, or, S + W = 400\r<BR>\n" );
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document.write( "S - W = 300 ------ (i)<BR>\n" );
document.write( "S + W = 400 ------ (ii)\r<BR>\n" );
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document.write( "2S = 700 ------- Adding eqs (i) & (ii)\r<BR>\n" );
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document.write( "S, or speed of plane = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=700%2F2 ALIGN=MIDDLE  ALT=\"700%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28350%29 ALIGN=MIDDLE  ALT=\"highlight_green%28350%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph\r<BR>\n" );
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document.write( "Substituting 350 for S in eq (i), we get:\r<BR>\n" );
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document.write( "350 - W = 300\r<BR>\n" );
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document.write( "- W = - 50\r<BR>\n" );
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document.write( "W, or windspeed = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-50%29%2F-1 ALIGN=MIDDLE  ALT=\"%28-50%29%2F-1\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%2850%29 ALIGN=MIDDLE  ALT=\"highlight_green%2850%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph </SPAN>\n" );
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