document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=875422>Question 875422</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jose rode his boat 4 kilometers up a stream and then returned the same distance. The current in the stream was flowing at a speed of 3 km/h. If the round trip took JOse 1 hour and 20 minutes, find speed of his boat 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 #528160 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=528160\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> boat   	speed	x   	km/h		Time forward + time return = hours												<BR>\n" );
document.write( "current     	speed	3	km/h														<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=	4	miles															<BR>\n" );
document.write( "																	<BR>\n" );
document.write( "Time against + time with  =			5/3	hours													<BR>\n" );
document.write( "t=d/r																	<BR>\n" );
document.write( "																	<BR>\n" );
document.write( "4	/(	x   	+	3	)	+	4	/(x	-	3	)	=	5/3				<BR>\n" );
document.write( "																	<BR>\n" );
document.write( "LCD =	(x	-	3	)	(	x   	+	3	)								<BR>\n" );
document.write( "4	*(	x   	-	3	)	+	4	(x	+	3	)	=	5/3	(x^2	-	9	)<BR>\n" );
document.write( "4	x   	-	-12	+	4	x   	+	12		=	5/3	(	x ^2		-	9	)<BR>\n" );
document.write( "8	x   	=	5/3	x ^2		-15											<BR>\n" );
document.write( "5/3	x ^2		-8	x   	-	15	=	0\r<BR>\n" );
document.write( "\n" );
document.write( "5x^2-24x-45=0\r<BR>\n" );
document.write( "\n" );
document.write( "Find the roots of the equation by quadratic formula							<BR>\n" );
document.write( "							<BR>\n" );
document.write( "a=	5	,	b=	-24	,	c=	-45<BR>\n" );
document.write( "							<BR>\n" );
document.write( "b^2-4ac=	576	+	900				<BR>\n" );
document.write( "b^2-4ac=	1476						<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%09sqrt%28%091476%09%29=%0938.42%09 ALIGN=MIDDLE  ALT=\"%09sqrt%28%091476%09%29=%0938.42%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=(	24	+	38.42	)/	10		<BR>\n" );
document.write( "x1=	6.24						<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=(	24	-38.42	) /	10			<BR>\n" );
document.write( "x2=	-1.44						<BR>\n" );
document.write( "Ignore negative value							<BR>\n" );
document.write( "boat   	speed	6.242	km/h				<BR>\n" );
document.write( "									<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );