document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=263127>Question 263127</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The speed of a stream is 4 mph.  A boat travels 7 miles upstream in the same time it takes to travel 15 miles downstream.  What is the speed of the boat in still water?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #193879 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=193879\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The speed of a stream is 4 mph. A boat travels 7 miles upstream in the same time it takes to travel 15 miles downstream. What is the speed of the boat in still water?<BR>\n" );
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document.write( "Upstream DATA:<BR>\n" );
document.write( "distance = 7 miles ; rate = x-4 mph ; time = d/r = 7/(x-4) hrs.<BR>\n" );
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document.write( "Downstream DATA:<BR>\n" );
document.write( "distance = 15 miles ; rate = x+4 mph ; time = 15/(x+4) hrs<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "time = time<BR>\n" );
document.write( "7/(x-4) = 15/(x+4)<BR>\n" );
document.write( "7(x+4) = 15(x-4)<BR>\n" );
document.write( "7x+28 = 15x-60<BR>\n" );
document.write( "8x = 88<BR>\n" );
document.write( "x = 11 mph (rate in still water)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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