document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=994774>Question 994774</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane flies 435 miles in the wind and 345 miles against the wind in the same length of time.  If the speed of the wind is 15 miles per hour,  find the speed of 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 #613775 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39620)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=613775\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a very common form of uniform travel rates exercise.  The solution here will be generalized.\r<BR>\n" );
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document.write( "RT=D relates rate (or speed), time, and distance.\r<BR>\n" );
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document.write( "VARIABLES<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28r=unknownSpeedNoWind%2Cw=speedOfWind%2CD=DistanceWithWind%2Cd=DistanceAgainstWind%2Ct=unknownTimeBothDirections%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "Direction           speed            time         distance\r\n" );
document.write( "WITHWIND            r+w               t            D\r\n" );
document.write( "AGAINSTWIND         r-w               t            d\r\n" );
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document.write( "Find the two expressions, formulas, for t.<BR>\n" );
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document.write( "Direction           speed            time         distance\r\n" );
document.write( "WITHWIND            r+w              D/(r+w)       D\r\n" );
document.write( "AGAINSTWIND         r-w              d/(r-w)       d\r\n" );
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document.write( "Those two times were given as equal.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28D%2F%28r%2Bw%29=d%2F%28r-w%29%29 ALIGN=MIDDLE  ALT=\"highlight%28D%2F%28r%2Bw%29=d%2F%28r-w%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The only unknown variable in this equation is r, the rate of the vehicle in still air.\r<BR>\n" );
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document.write( "SOLUTION STEPS FOR THE ARITHMETIC<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D%28r-w%29=d%28r%2Bw%29 ALIGN=MIDDLE  ALT=\"D%28r-w%29=d%28r%2Bw%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Dr-Dw=dr%2Bdw ALIGN=MIDDLE  ALT=\"Dr-Dw=dr%2Bdw\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Dr-dr-Dw=dw ALIGN=MIDDLE  ALT=\"Dr-dr-Dw=dw\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Dr-dr=dw%2BDw ALIGN=MIDDLE  ALT=\"Dr-dr=dw%2BDw\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28D-d%29r=dw%2BDw ALIGN=MIDDLE  ALT=\"%28D-d%29r=dw%2BDw\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28highlight%28r=%28dw%2BDw%29%2F%28D-d%29%29%29 ALIGN=MIDDLE  ALT=\"highlight%28highlight%28r=%28dw%2BDw%29%2F%28D-d%29%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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