document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=205884>Question 205884</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The speed of a boat in still water is 15 km/h. The boat travels 40 km upstream and 40 km downstream in a total of 6 hours. What is the speed of the stream? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #155515 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=155515\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> time = distance / rate<BR>\n" );
document.write( "total time is 6 hrs\r<BR>\n" );
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document.write( "let s=\"speed of stream\"\r<BR>\n" );
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document.write( "[40 / (15 + s)] + [40 / (15 - s)] = 6\r<BR>\n" );
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document.write( "multiplying by (15 + s)(15 - s) ___ 600 - 40s + 600 + 40s = 1350 - 6s^2\r<BR>\n" );
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document.write( "0 = 150 - 6s^2 ___ 0 = 25 - s^2 ___ s = 5 </SPAN>\n" );
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