document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=534938>Question 534938</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A truck traveled the first 90 miles of a trip at one speed and the last 80 miles at an average speed of 5 miles per hour less. The entire trip took 4 hours. What was the average speed for the first part of the trip? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #351706 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=351706\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> first part	90	miles										<BR>\n" );
document.write( "second part	80	miles										<BR>\n" );
document.write( "												<BR>\n" );
document.write( "speed in first part	x			mph								<BR>\n" );
document.write( "speed second part	x		-5	mph								<BR>\n" );
document.write( "Total rowing time		2	hours									<BR>\n" );
document.write( "Time first part		90	/	x								<BR>\n" );
document.write( "Time second part		80	/	(	x	-5	)					<BR>\n" );
document.write( "												<BR>\n" );
document.write( "Time first part + time second part =			4	hours								<BR>\n" );
document.write( "												<BR>\n" );
document.write( "90	/	x				+	80	/(x	-5	)	=	2<BR>\n" );
document.write( "LCD =	(	x	+	0	)*	(x	-5	)				<BR>\n" );
document.write( "multiply the equation by the LCD												<BR>\n" );
document.write( "we get												<BR>\n" );
document.write( "90	*	(x	-5	)+	80		x				=	2<BR>\n" );
document.write( "90	x	-450	+	80	x				=	2	X^2	<BR>\n" );
document.write( "180	x	-450	=	2	X^2							<BR>\n" );
document.write( "2	X^2	-180	x	450			=	0				<BR>\n" );
document.write( "2	X^2+	-180	x+	450	=							<BR>\n" );
document.write( "/	2											<BR>\n" );
document.write( "1	X^2	-90	x	225	=				<BR>\n" );
document.write( "Find the roots of the equation by quadratic formula				<BR>\n" );
document.write( "a=	1	b=	-90	c=	225				<BR>\n" );
document.write( "b^2-4ac=	8100	-	-900									<BR>\n" );
document.write( "b^2-4ac=	7200\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%097200%09%29 ALIGN=MIDDLE  ALT=\"sqrt%28%097200%09%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >=	84.85<BR>\n" );
document.write( "					<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=(	90	+	84.85	)/	2							<BR>\n" );
document.write( "x1=	87.43		87 3/7									<BR>\n" );
document.write( "x2=(	90	-84.85	) /	2								<BR>\n" );
document.write( "x2= 	2.57		2 4/7									<BR>\n" );
document.write( "Ignore negative value												<BR>\n" );
document.write( "x	=	87.43	mph	LCD =		speed						<BR>\n" );
document.write( "												<BR>\n" );
document.write( "CHECK												<BR>\n" );
document.write( "Time first part	+	Time second part										<BR>\n" );
document.write( "1.03	+	0.97	=	2								<BR>\n" );
document.write( "												<BR>\n" );
document.write( "												<BR>\n" );
document.write( "m.ananth@hotmail.ca												<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );