document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=304035>Question 304035</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In 8 hours, two campers rowed 15 miles down a river and then rowed back to their campsite. The rate of the river's current was 1 mph. Find the rate at which the campers row in calm water.\r<BR>\n" );
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document.write( "What I know is that it was 8 hours total and it took 15 mi there and back.\r<BR>\n" );
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document.write( "Please help! I've been trying to solve it for now an hour and 31 minutes. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #217826 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=217826\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let the speed of the boat be xmph in still water\r<BR>\n" );
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document.write( "down stream the speed will be x+1 mph\r<BR>\n" );
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document.write( "time taken down stream = 15 / x+1 hours\r<BR>\n" );
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document.write( "upstream the speed will be x-1 mph\r<BR>\n" );
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document.write( "time taken upstream = 15 / x-1\r<BR>\n" );
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document.write( "sum of these two times = 8 hours\r<BR>\n" );
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document.write( "15 / x+1 + 15 /x-1 = 8\r<BR>\n" );
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document.write( "15(x-1)+15(x+1) / x^2-1= 8\r<BR>\n" );
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document.write( "15x-15 +15x +15 = 8(x^2-1)\r<BR>\n" );
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document.write( "30x = 8x^2-8\r<BR>\n" );
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document.write( "8x^2-30x-8 =0\r<BR>\n" );
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document.write( "8x^2-32x+2x-8=0\r<BR>\n" );
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document.write( "8x(x-4)+2(x-4)=0\r<BR>\n" );
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document.write( "(x-4)(8x+2)=0\r<BR>\n" );
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document.write( "x= 4 or -2/8\r<BR>\n" );
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document.write( "the rowing speed in still waters = 4 mph  </SPAN>\n" );
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