document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=142586>Question 142586</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An airplane flies 900 miles against the wind and 1200 miles with the wind in a total time of 15 hours.  The speed of the airplane in still air is 150 mph.  What is the speed 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 #103786 by </B><A HREF=/tutors/aboutme.mpl?userid=vleith><B>vleith(2983)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=vleith><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=103786\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Distance = velocity * time.\r<BR>\n" );
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document.write( "total time = 15 hours. <BR>\n" );
document.write( "Distance against wind, 900 miles<BR>\n" );
document.write( "Distance with wind, 1200 miles<BR>\n" );
document.write( "Ground speed, 150 mph. \r<BR>\n" );
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document.write( "Let the wind speed be w.<BR>\n" );
document.write( "Let the time flow against the wind be t. that means the time flown with the wind is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15+-+t ALIGN=MIDDLE  ALT=\"15+-+t\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Construct two equations, as follows.<BR>\n" );
document.write( "Against wind<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=900+=+%28150+-+w%29+%2A+t ALIGN=MIDDLE  ALT=\"900+=+%28150+-+w%29+%2A+t\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=900%2F%28150-w%29+=+t ALIGN=MIDDLE  ALT=\"900%2F%28150-w%29+=+t\"   DISABLED_style= \"max-width:90%; height:auto;\" >     <--- use this later\r<BR>\n" );
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document.write( "With wind:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1200+=+%28150+%2B+w%29+%2A+%2815-t%29 ALIGN=MIDDLE  ALT=\"1200+=+%28150+%2B+w%29+%2A+%2815-t%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1200+=+2250+%2B+15w+-+150t+-+wt ALIGN=MIDDLE  ALT=\"1200+=+2250+%2B+15w+-+150t+-+wt\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-1050+=+15w+-+150t+-+wt ALIGN=MIDDLE  ALT=\"-1050+=+15w+-+150t+-+wt\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Use the value for t from above.<BR>\n" );
document.write( "Substitute that t in the last equation and solve for w. There will be two answers, pck the one that 'makes sense'.<BR>\n" );
document.write( " </SPAN>\n" );
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