document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=761829>Question 761829</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 2 cities are 1980 miles apart. one trip flying into the wind took 5.5 hours, the return trip with the wind took only 4.5 hours. what is the speed of the wind and the plane in still air </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #463568 by </B><A HREF=/tutors/aboutme.mpl?userid=ramkikk66><B>ramkikk66(644)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ramkikk66><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=463568\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let x be the speed of plane in still air and y be the wind speed.\r<BR>\n" );
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document.write( "Step 1: Flying into the wind, effective speed = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x+-+y%29 ALIGN=MIDDLE  ALT=\"%28x+-+y%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. Distance of 1980 is covered in 5.5 hours. Distance = Speed * time.<BR>\n" );
document.write( "So<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x+-+y%29+%2A+5.5+=+1980 ALIGN=MIDDLE  ALT=\"%28x+-+y%29+%2A+5.5+=+1980\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+-+y+=+1980%2F5.5+=+360 ALIGN=MIDDLE  ALT=\"x+-+y+=+1980%2F5.5+=+360\"   DISABLED_style= \"max-width:90%; height:auto;\" >  ---> eqn 1\r<BR>\n" );
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document.write( "Step 2: Flying with the wind - effective speed = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x+%2B+y%29 ALIGN=MIDDLE  ALT=\"%28x+%2B+y%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Applying the same formula distance = speed * time\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x+%2B+y%29+%2A+4.5+=+1980 ALIGN=MIDDLE  ALT=\"%28x+%2B+y%29+%2A+4.5+=+1980\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+%2B+y+=+1980%2F4.5+=+440 ALIGN=MIDDLE  ALT=\"x+%2B+y+=+1980%2F4.5+=+440\"   DISABLED_style= \"max-width:90%; height:auto;\" > --- eqn 2\r<BR>\n" );
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document.write( "Step 3:<BR>\n" );
document.write( "From eqn 1, x = y + 360. Substituting for x in eqn 2\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+%2B+360+%2B+y+=+440 ALIGN=MIDDLE  ALT=\"y+%2B+360+%2B+y+=+440\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2Ay+=+80 ALIGN=MIDDLE  ALT=\"2%2Ay+=+80\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+40 ALIGN=MIDDLE  ALT=\"y+=+40\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Step 4:<BR>\n" );
document.write( "Since y = 40, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+y+%2B+360+=+400 ALIGN=MIDDLE  ALT=\"x+=+y+%2B+360+=+400\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Speed of plane in still air = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28400%29 ALIGN=MIDDLE  ALT=\"highlight%28400%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > and wind speed = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%2840%29 ALIGN=MIDDLE  ALT=\"highlight%2840%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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