document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=327892>Question 327892</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A river flows at a rate of 4 km./hr. for the length of its scenic route. In order for a boat to travel the 60 km. upriver and then return in a total of 8 hours, how fast must the boat be able to travel 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 #234844 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=234844\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 60/(x-4)+60/(x+4)= 8<BR>\n" );
document.write( "60(x+4)+60(x-4)/ (x^2-16)=8<BR>\n" );
document.write( "60x+240+60x-240=8(x^2-16)<BR>\n" );
document.write( "120x=8x^2-128<BR>\n" );
document.write( "add -120x to both sides<BR>\n" );
document.write( "120x-120x = 8x^2-120x-128<BR>\n" );
document.write( "8x^2-120x-128=0<BR>\n" );
document.write( "divide by 8<BR>\n" );
document.write( "x^2-15x-16=0<BR>\n" );
document.write( "x^2-16x+x-16=0<BR>\n" );
document.write( "x(x-16)+1(x-16)=0<BR>\n" );
document.write( "(x-16)(x+1)=0<BR>\n" );
document.write( "x= 16 OR -1 ignore negative value<BR>\n" );
document.write( "So the speed in still water = 16 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );