document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=384264>Question 384264</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the speed of a boat in still water is 16 km/h.The boat travels 43 km upstream and 45 km downstream in a total time of 20 hr.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 #272097 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=272097\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the speed of a boat in still water is 16 km/h.The boat travels 43 km upstream and 45 km downstream in a total time of 20 hr.what is the speed of the stream?<BR>\n" );
document.write( "...<BR>\n" );
document.write( "speed of boat = 16km/h<BR>\n" );
document.write( "speed of current = x km/h<BR>\n" );
document.write( "..<BR>\n" );
document.write( "upstream speed = 16-x<BR>\n" );
document.write( "downstream speed = 16+x<BR>\n" );
document.write( "..<BR>\n" );
document.write( "d upstream = 43 km<BR>\n" );
document.write( "d downstream = 45 km<BR>\n" );
document.write( "..<BR>\n" );
document.write( "43/(16-x)+45/(16+x)= 20<BR>\n" );
document.write( "...<BR>\n" );
document.write( "LCD = (16+x)(16-x)<BR>\n" );
document.write( "43(16+x)+45(16-x)/(16+x)(16-x)=20<BR>\n" );
document.write( "688+43x+720-45x/16+x)(16-x)=20<BR>\n" );
document.write( "1408-2x=20(256-x^2)<BR>\n" );
document.write( "1408-2x=5120-20x^2<BR>\n" );
document.write( "20x^2-2x=5120-1408<BR>\n" );
document.write( "20x^2-2x=3712<BR>\n" );
document.write( "20x^2-2x-3712=0<BR>\n" );
document.write( "..<BR>\n" );
document.write( "solve for roots x1 & x2 using quadratic equation<BR>\n" );
document.write( "discriminant =296964<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x1=%282%2Bsqrt%28296964%29%29%2F%2840%29 ALIGN=MIDDLE  ALT=\"x1=%282%2Bsqrt%28296964%29%29%2F%2840%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x1= 13.7 km/h the speed of current.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x2=%282-sqrt%28296964%29%29%2F%2840%29 ALIGN=MIDDLE  ALT=\"x2=%282-sqrt%28296964%29%29%2F%2840%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x2 will be negative so ignore.<BR>\n" );
document.write( "...<BR>\n" );
document.write( "13.7 km/h the speed of current.<BR>\n" );
document.write( "...<BR>\n" );
document.write( "m.ananth@hotmail.ca </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );