document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=875628>Question 875628</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve this problem:<BR>\n" );
document.write( "Suppose it took you 30 minutes less to drive the 40 miles back home after dinner at your parent's house than it did for you to arrive there in rush-hour traffic. You drove about 15 mph faster on the way home. How fast did you drive each way? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #528375 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=528375\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> going	speed	x					<BR>\n" );
document.write( "returning	speed	x	+	15			<BR>\n" );
document.write( "							<BR>\n" );
document.write( "	Distance = same		40	miles	0.5		<BR>\n" );
document.write( "	original time – time with increased speed =					0.5	hour<BR>\n" );
document.write( "	t=d/t						\r<BR>\n" );
document.write( "\n" );
document.write( "40	/	x	-	40	/	(	x	+	10	)	=	0.5				<BR>\n" );
document.write( "LCD=	x	(	x	+	15	)										<BR>\n" );
document.write( "multiply by LCD																<BR>\n" );
document.write( "40	(	x	+	15	)	-	40	x	=	0.5	x	(	x	+	15	)<BR>\n" );
document.write( "40	x	+	600	-	40	x	=	0.5	X^2	+	7.5	x				<BR>\n" );
document.write( "600	=	0.5	X^2	+	7.5	x										<BR>\n" );
document.write( "0.5	X^2		+	7.5	x	-	-600	=	0							<BR>\n" );
document.write( "Find roots of the quadratic equation																<BR>\n" );
document.write( "a=	0.5		b=	7.5		c=	-600									<BR>\n" );
document.write( "																<BR>\n" );
document.write( "x1=	(	-7.5	+	sqrt(		56.25	-	1200	))	/	1					<BR>\n" );
document.write( "x1=(	-7.5	+	35.44	)/	1											<BR>\n" );
document.write( "x1=	27.94															<BR>\n" );
document.write( "																<BR>\n" );
document.write( "x2=	(	-7	-	sqrt(		49	-	20	)	/	2					<BR>\n" );
document.write( "x2=(	-7.5	-	35.44	)/	1											<BR>\n" );
document.write( "x2=	-42.94															<BR>\n" );
document.write( "ignore negative\r<BR>\n" );
document.write( "\n" );
document.write( "going speed was 27.94 mph\r<BR>\n" );
document.write( "\n" );
document.write( "add 15 for returning speed </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );