document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=937920>Question 937920</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A 150 minute river cruise goes 14km upstream and then back again. The river has a current of 3km an hour going downstream. What is the boat's speed in still water and how long was the upstream journey in minutes? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #571346 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=571346\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> boat   	speed	x   	km 		Time forward + time return = hours		<BR>\n" );
document.write( "current     	speed	3	km 				<BR>\n" );
document.write( "							<BR>\n" );
document.write( "against	current     	x-	3	km/h			<BR>\n" );
document.write( "with	current     	x+	3	km/h			<BR>\n" );
document.write( "							<BR>\n" );
document.write( "Distance=	14	km 					<BR>\n" );
document.write( "							<BR>\n" );
document.write( "Time against + time with  =			2.5	hours			<BR>\n" );
document.write( "t=d/r							<BR>\n" );
document.write( "							<BR>\n" );
document.write( "14	/(	x   	+	3	)	+	14<BR>\n" );
document.write( "							<BR>\n" );
document.write( "LCD =	(x	-	3	)	(	x   	+<BR>\n" );
document.write( "14	*(	x   	-	3	)	+	14<BR>\n" );
document.write( "14	x   	-	-42	+	14	x   	+<BR>\n" );
document.write( "28	x   	=	2.5	x ^2		-22.5	<BR>\n" );
document.write( "2.5	x ^2	-	-28	x   	-	-22.5	=<BR>\n" );
document.write( "							<BR>\n" );
document.write( "Find the roots of the equation by quadratic formula							<BR>\n" );
document.write( "							<BR>\n" );
document.write( "a=	2.5	,	b=	-28	,	c=	-22.5<BR>\n" );
document.write( "							<BR>\n" );
document.write( "b^2-4ac=	784	+	225				<BR>\n" );
document.write( "b^2-4ac=	1009						<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%09sqrt%28%091009%09%29=%0931.76%09 ALIGN=MIDDLE  ALT=\"%09sqrt%28%091009%09%29=%0931.76%09\"   DISABLED_style= \"max-width:90%; height:auto;\" >		<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >							<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >							<BR>\n" );
document.write( "x1=(	28	+	31.76	)/	5		<BR>\n" );
document.write( "x1=	11.95						<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x2=%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x2=%28-b-sqrt%28b%5E2-4ac%29%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >							<BR>\n" );
document.write( "x2=(	28	-31.76	) /	5			<BR>\n" );
document.write( "x2=	-0.75						<BR>\n" );
document.write( "Ignore negative value							<BR>\n" );
document.write( "boat   	speed	11.953	km/h	\r<BR>\n" );
document.write( "\n" );
document.write( "Time upstream = 	(14/8.953)*60		=94 minutes<BR>\n" );
document.write( "							<BR>\n" );
document.write( "m.ananth@hotmail.ca							<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );