document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=688084>Question 688084</A>: <I><SPAN STYLE=\"word-break: break-all;\">  A boat travels 9 miles downstream in the same time it takes to go 6 miles upstream. If the speed of the current is 4 mph, what is the speed of the boat? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #425497 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=425497\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A boat travels 9 miles downstream in the same time it takes to go 6 miles upstream. If the speed of the current is 4 mph, what is the speed of the boat?<BR>\n" );
document.write( "**<BR>\n" );
document.write( "let x=speed of boat in still water<BR>\n" );
document.write( "x+4=speed of boat downstream<BR>\n" );
document.write( "x-4=speed of boat upstream<BR>\n" );
document.write( "travel time=distance/speed (same for upstream and downstream travel)<BR>\n" );
document.write( "9/(x+4)=6/(x-4)<BR>\n" );
document.write( "9x-36=6x+24<BR>\n" );
document.write( "3x=60<BR>\n" );
document.write( "x=20<BR>\n" );
document.write( "speed of boat=20 mph </SPAN>\n" );
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