document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=813203>Question 813203</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Ian paddled a canoe 7 miles upstream in a river that has a current of 4 mph. He then turned around and paddled downstream until he reached his original starting place. If the entire trip took him 6 hours, how fast would Ian paddle 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 #489522 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=489522\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Ian paddled a canoe 7 miles upstream in a river that has a current of 4 mph. He then turned around and paddled downstream until he reached his original starting place. If the entire trip took him 6 hours, how fast would Ian paddle in still water?<BR>\n" );
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document.write( "Upstream DATA:<BR>\n" );
document.write( "distance = 7 miles ; rate = b-4 mph ; time = d/r = 7/(b-4) hrs<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "Downstream DATA:<BR>\n" );
document.write( "distance = 7 miles ; rate = b+4 mph ; time = d/r = 7/(b+4) hrs<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "time + time = 6 hrs<BR>\n" );
document.write( "7/(b-4) + 7/(b+4) = 6<BR>\n" );
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document.write( "7(b+4) + 7(b-4) = 6(b^2-16)<BR>\n" );
document.write( "14b = 6b^2 - 96<BR>\n" );
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document.write( "3b^2 - 7b -48 = 0<BR>\n" );
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document.write( "Positive solution::<BR>\n" );
document.write( "b = 5 1/3 mph (Ian's rate in still water)<BR>\n" );
document.write( "======================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "======================<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );