document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=892313>Question 892313</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A plane goes 150 miles with the wind and returns against the wind in 3 hours and 45minutes. Find the air speed if the plane if the wind blows 10mph. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #540422 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39618)</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=540422\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> SEE FARTHER BELOW FOR  A MUCH BETTER SOLUTION PLAN!\r<BR>\n" );
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document.write( "r is speed without wind.\r<BR>\n" );
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document.write( "_____________________speed_________time___________distance<BR>\n" );
document.write( "WITH_________________r+10__________x___________(r+10)x<BR>\n" );
document.write( "AGAINST______________r-10__________y___________(r-10)y<BR>\n" );
document.write( "Totals____________________________3&3/4_________150\r<BR>\n" );
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document.write( "SYSTEM FORMULATED INITIALLY<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%2By=3%263%2F4 ALIGN=MIDDLE  ALT=\"x%2By=3%263%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28r%2B10%29x%2B%28r-10%29y=150 ALIGN=MIDDLE  ALT=\"%28r%2B10%29x%2B%28r-10%29y=150\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "The way that the situation would become simpler to analyze is that the plane would travel equal distances with as against the wind.  Exactly how is your given problem written?  If equal distances in both directions,\r<BR>\n" );
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document.write( "_____________________speed_________time________distance<BR>\n" );
document.write( "WITH_________________r+10__________x___________(r+10)x=d<BR>\n" );
document.write( "AGAINST______________r-10__________y___________(r-10)y=d<BR>\n" );
document.write( "Totals____________________________3&3/4_________150\r<BR>\n" );
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document.write( "And you can include <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28r%2B10%29x=%28r-10%29y ALIGN=MIDDLE  ALT=\"%28r%2B10%29x=%28r-10%29y\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "You also say <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28r%2B10%29x=75 ALIGN=MIDDLE  ALT=\"%28r%2B10%29x=75\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28r-10%29y=75 ALIGN=MIDDLE  ALT=\"%28r-10%29y=75\"   DISABLED_style= \"max-width:90%; height:auto;\" > which may allow elimination of r to solve for x and y.\r<BR>\n" );
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document.write( "rx+10x=75 and ry-10y=75;<BR>\n" );
document.write( "rx=75-10x and ry=75+10y;<BR>\n" );
document.write( "r=(75-10x)/x and r=(75+10y)/y;<BR>\n" );
document.write( "Equate the expression of r;<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2875-10x%29%2Fx=%2875%2B10y%29%2Fy ALIGN=MIDDLE  ALT=\"%2875-10x%29%2Fx=%2875%2B10y%29%2Fy\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=75y-10xy=75x%2B10xy ALIGN=MIDDLE  ALT=\"75y-10xy=75x%2B10xy\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=75y-75x-10xy-10xy=0 ALIGN=MIDDLE  ALT=\"75y-75x-10xy-10xy=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=75y-75x-20xy=0 ALIGN=MIDDLE  ALT=\"75y-75x-20xy=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=75x-75y%2B20xy=0 ALIGN=MIDDLE  ALT=\"75x-75y%2B20xy=0\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%2815x-15y%2B4xy=0%29 ALIGN=MIDDLE  ALT=\"highlight_green%2815x-15y%2B4xy=0%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Now recall earlier the equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28x%2By=3%263%2F4%29 ALIGN=MIDDLE  ALT=\"highlight_green%28x%2By=3%263%2F4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "Two equation in the unknowns x and y.  Solve them and then use for finding r.\r<BR>\n" );
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document.write( "The above shown solution method now seems overly complicated.<BR>\n" );
document.write( "Assuming equal distance to and from, then each way is 75 miles.<BR>\n" );
document.write( "RT=D allows us to make expressions for the time in each direction.\r<BR>\n" );
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document.write( "___________________speed_________time_________________distance<BR>\n" );
document.write( "WITH_______________r+10__________75/(r+10)____________75<BR>\n" );
document.write( "AGAINST____________r-10__________75/(r-10)____________75<BR>\n" );
document.write( "Total____________________________3&3/4\r<BR>\n" );
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document.write( "Now only need to solve for r in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%2875%2F%28r%2B10%29%2B75%2F%28r-10%29=3%263%2F4%29 ALIGN=MIDDLE  ALT=\"highlight%2875%2F%28r%2B10%29%2B75%2F%28r-10%29=3%263%2F4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >. </SPAN>\n" );
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