document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=802147>Question 802147</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jamie recently drove to visit her parents who live 390 miles away. On her way there her average speed was 11 miles per hour faster than on her way home (she ran into some bad weather). If Jamie spent a total of 13 hours driving, find the two rates. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #483784 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=483784\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Jamie recently drove to visit her parents who live 390 miles away. On her way there her average speed was 11 miles per hour faster than on her way home (she ran into some bad weather). If Jamie spent a total of 13 hours driving, find the two rates.\r<BR>\n" );
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document.write( "distance = 390 miles<BR>\n" );
document.write( "on her way there speed = x mph\r<BR>\n" );
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document.write( "time taken = 930/x\r<BR>\n" );
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document.write( "On her return speed was x-11 mph\r<BR>\n" );
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document.write( "time = 930/(x-11)\r<BR>\n" );
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document.write( "Time to go there + time to return = 13 hours\r<BR>\n" );
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document.write( "930/x +930/(x-11) = 13\r<BR>\n" );
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document.write( "Multiply by x(x-11)\r<BR>\n" );
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document.write( "930(x-11)+930x=13x(x-11)\r<BR>\n" );
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document.write( "930x-10230+930x=13x^2-143x\r<BR>\n" );
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document.write( "Re arrange\r<BR>\n" );
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document.write( "13x^2-1860x-143x+10230=0\r<BR>\n" );
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document.write( "13x^2-2003x+10230=0\r<BR>\n" );
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document.write( "Find the roots of the equation by quadratic formula									<BR>\n" );
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document.write( "a=	13    	b=	-2003	c=	10230		2916		<BR>\n" );
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document.write( "b^2-4ac=	4012009	-	531960						<BR>\n" );
document.write( "b^2-4ac=	3480049		<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%093480049%09%29 ALIGN=MIDDLE  ALT=\"sqrt%28%093480049%09%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >=	1865.49			<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=(	2003	+	1865.49	)/	26				<BR>\n" );
document.write( "x1=	148.79								<BR>\n" );
document.write( "x2=(	2003	-	1865.49	)/	26				<BR>\n" );
document.write( "x2=	5.29								<BR>\n" );
document.write( "Ignore 5.29 									<BR>\n" );
document.write( "x	=	148.79	mph	to go there\r<BR>\n" );
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document.write( "Return will be 11 mph less\r<BR>\n" );
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document.write( " </SPAN>\n" );
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