document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=835576>Question 835576</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane can fly 320 mph in still air. If it can fly 185 miles downwind in the same amount of time it can fly 135 miles upwind, find the velocity of the wind. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #503628 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=503628\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+w+ ALIGN=MIDDLE  ALT=\"+w+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the velocity of the wind<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+320+%2B+w+ ALIGN=MIDDLE  ALT=\"+320+%2B+w+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the plane's speed flying downwind<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+320+-+w+ ALIGN=MIDDLE  ALT=\"+320+-+w+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the plane's speed flying upwind<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the time in hours for either trip<BR>\n" );
document.write( "---------------------------------------<BR>\n" );
document.write( "Equation for flying downwind:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+185+=+%28+320+%2B+w+%29%2At+ ALIGN=MIDDLE  ALT=\"+185+=+%28+320+%2B+w+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Equation for flying upwind:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+135+=+%28+320+-+w+%29%2At+ ALIGN=MIDDLE  ALT=\"+135+=+%28+320+-+w+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "------------------------<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+185+%2F+%28+320+%2B+w+%29+ ALIGN=MIDDLE  ALT=\"+t+=+185+%2F+%28+320+%2B+w+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+135+%2F+%28+320+-+w+%29+ ALIGN=MIDDLE  ALT=\"+t+=+135+%2F+%28+320+-+w+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "By substitution:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+185+%2F+%28+320+%2B+w+%29+=+135+%2F+%28+320+-+w+%29+ ALIGN=MIDDLE  ALT=\"+185+%2F+%28+320+%2B+w+%29+=+135+%2F+%28+320+-+w+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+320+%2B+w+%29%2A%28+320+-+w+%29+ ALIGN=MIDDLE  ALT=\"+%28+320+%2B+w+%29%2A%28+320+-+w+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+185%2A%28+320+-+w+%29+=+135%2A%28+320+%2B+w+%29+ ALIGN=MIDDLE  ALT=\"+185%2A%28+320+-+w+%29+=+135%2A%28+320+%2B+w+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+59200+-+185w+=+43200+%2B+135w+ ALIGN=MIDDLE  ALT=\"+59200+-+185w+=+43200+%2B+135w+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+320w+=+16000+ ALIGN=MIDDLE  ALT=\"+320w+=+16000+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+w+=+50+ ALIGN=MIDDLE  ALT=\"+w+=+50+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The wind speed is 50 mi/hr<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+185+%2F+%28+320+%2B+50+%29+ ALIGN=MIDDLE  ALT=\"+t+=+185+%2F+%28+320+%2B+50+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+185%2F370+ ALIGN=MIDDLE  ALT=\"+t+=+185%2F370+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+.5+ ALIGN=MIDDLE  ALT=\"+t+=+.5+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+135+%2F+%28+320+-+50+%29+ ALIGN=MIDDLE  ALT=\"+t+=+135+%2F+%28+320+-+50+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+135+%2F+270+ ALIGN=MIDDLE  ALT=\"+t+=+135+%2F+270+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+.5+ ALIGN=MIDDLE  ALT=\"+t+=+.5+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "OK\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );