document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=415092>Question 415092</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If Alexandra increases her usual driving speed by 15 km/h, it will take her 2h less to make a trip to her grandparents' house. If she decreases her usual speed by 15 km/h, it will take her 3 h more than usual to make the trip. How long is 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 #291066 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=291066\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If Alexandra increases her usual driving speed by 15 km/h, it will take her 2h less to make a trip to her grandparents' house. If she decreases her usual speed by 15 km/h, it will take her 3 h more than usual to make the trip. How long is the trip?\r<BR>\n" );
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document.write( "let usual speed = x mph<BR>\n" );
document.write( "speed increased by 15km/h<BR>\n" );
document.write( "speed = x+15 km/h<BR>\n" );
document.write( "...<BR>\n" );
document.write( "usual time = y<BR>\n" );
document.write( "time with increased speed = y-2\r<BR>\n" );
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document.write( "xy = (x+15)(y-2)<BR>\n" );
document.write( "xy=xy-2x+15y-30<BR>\n" );
document.write( "2x-15y=-30.....................1\r<BR>\n" );
document.write( "\n" );
document.write( "...<BR>\n" );
document.write( "speed decreased by 15 km/h<BR>\n" );
document.write( "time = y+3<BR>\n" );
document.write( "..<BR>\n" );
document.write( "xy = (x-15)(y+3)<BR>\n" );
document.write( "xy=xy+3x-15y-45<BR>\n" );
document.write( "3x+15y=-45....................2\r<BR>\n" );
document.write( "\n" );
document.write( "2x-15y=-30.....................1\r<BR>\n" );
document.write( "\n" );
document.write( "...<BR>\n" );
document.write( "speed decreased by 15 km/h<BR>\n" );
document.write( "time = y+3<BR>\n" );
document.write( "..<BR>\n" );
document.write( "xy = (x-15)(y+3)<BR>\n" );
document.write( "xy=xy+3x-15y-45<BR>\n" );
document.write( "3x+15y=-45....................2\r<BR>\n" );
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document.write( "2x-15y=-30.............1	<BR>\n" );
document.write( "-3x+15y	=-45	.............2	<BR>\n" );
document.write( "								<BR>\n" );
document.write( "multiply (1)by 					1			<BR>\n" );
document.write( "Multiply (2) by					1			<BR>\n" );
document.write( "2x-15y	=-30		<BR>\n" );
document.write( "-3x+15y	=-45		<BR>\n" );
document.write( "								<BR>\n" );
document.write( "Add the two equations							<BR>\n" );
document.write( "-1x=-75		<BR>\n" );
document.write( "/-1							<BR>\n" );
document.write( "x=75 km/h						<BR>\n" );
document.write( "								<BR>\n" );
document.write( "plug value of x in (1)							2x-15y	=-30		<BR>\n" );
document.write( "150-15y	=-30		<BR>\n" );
document.write( "-15y	=-30+-150<BR>\n" );
document.write( "-15y=-180		<BR>\n" );
document.write( "y=12	hours\r<BR>\n" );
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document.write( "Distance = speed * time<BR>\n" );
document.write( "Distance = 75*12= 900 km	<BR>\n" );
document.write( " </SPAN>\n" );
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