document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=136864>Question 136864</A>: <I><SPAN STYLE=\"word-break: break-all;\"> PROBLEM:<BR>\n" );
document.write( "DAVE IS FLYING FROM PHILADELPHIA TO CHICAGO. ON THE FLIGHT, FLYING AGAINST THE WIND, THE 780 MILE TRIP TAKES 2 HOURS. THE RETURN TRIP, WITH THE WIND TAKES 1.5 HOURS. FIND THE SPEED OF THE WIND AND FIND THE SPEED OF THE PLANE IN STILL AIR.\r<BR>\n" );
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document.write( "PLEASE HELP I DONT EVEN KNOW WHERE TO BEGIN THANKS!! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #100160 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=100160\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Do me a favor please.  Stop typing your questions in ALL CAPS.  It is rude, annoying, hard to read, and is the electronic equivalent of shouting.\r<BR>\n" );
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document.write( "The speed of the plane in still air: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r ALIGN=MIDDLE  ALT=\"r\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The speed of the wind <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Bw%5D ALIGN=MIDDLE  ALT=\"r%5Bw%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The speed of the plane against the wind: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r-r%5Bw%5D ALIGN=MIDDLE  ALT=\"r-r%5Bw%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The speed of the plane with the wind: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%2Br%5Bw%5D ALIGN=MIDDLE  ALT=\"r%2Br%5Bw%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Distance equals rate times time:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d=rt ALIGN=MIDDLE  ALT=\"d=rt\"   DISABLED_style= \"max-width:90%; height:auto;\" >, but this can be solved for rate: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=d%2Ft ALIGN=MIDDLE  ALT=\"r=d%2Ft\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "For the trip against the wind:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r-r%5Bw%5D=780%2F2=390 ALIGN=MIDDLE  ALT=\"r-r%5Bw%5D=780%2F2=390\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "For the trip with the wind: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%2Br%5Bw%5D=780%2F1.5=520 ALIGN=MIDDLE  ALT=\"r%2Br%5Bw%5D=780%2F1.5=520\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Add these two equations:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28r%2Br%5Bw%5D%29%2B%28r-r%5Bw%5D%29=910 ALIGN=MIDDLE  ALT=\"%28r%2Br%5Bw%5D%29%2B%28r-r%5Bw%5D%29=910\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2r=910 ALIGN=MIDDLE  ALT=\"2r=910\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=455 ALIGN=MIDDLE  ALT=\"r=455\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Check:<BR>\n" );
document.write( "If r is 455, then r[w] has to be 455 - 390 = 520 - 455 = 65.\r<BR>\n" );
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document.write( "So, against the wind, the plane goes 780 miles at 390 mph -- trip takes 2 hours<BR>\n" );
document.write( "With the wind, the plane goes 780 miles at 520 mph -- trip takes 1.5 hours.<BR>\n" );
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