document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=359421>Question 359421</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat cruises 36 miles against a 3 mph current and 36miles back in the direction of the same current. The round trip takes 5 hours. What is the speed of the boat in still water? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #256463 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=256463\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A boat cruises 36 miles against a 3 mph current and 36miles back in the direction of the same current. The round trip takes 5 hours. What is the speed of the boat in still water?<BR>\n" );
document.write( "..<BR>\n" );
document.write( "let speed of boat in still water be xmph<BR>\n" );
document.write( "upstream speed = x-3<BR>\n" );
document.write( "downstream speed = x+3<BR>\n" );
document.write( "..<BR>\n" );
document.write( "time = distance /speed<BR>\n" );
document.write( "36/(x-3)+36/(x+3)=5<BR>\n" );
document.write( "36(x+3)+36(x-3)=5(x^2-9)<BR>\n" );
document.write( "36x+108+36x-108=5x^2-45<BR>\n" );
document.write( "5x^2-72x-45=0<BR>\n" );
document.write( "5x^2-75x+3x-45=0<BR>\n" );
document.write( "5x(x-15)+3(x-15)=0<BR>\n" );
document.write( "(5x+3)(x-15)=0<BR>\n" );
document.write( "x= 15 mph --- speed of boat in still water<BR>\n" );
document.write( "...<BR>\n" );
document.write( "m.ananth@hotmail.ca </SPAN>\n" );
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