document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=875011>Question 875011</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Every morning at precisely 6:00 am, Susie begins her jogging circuit of the neighborhood. It’s a hilly route with no level stretches. Her uphill speed is always 2 miles per hour and her downhill speed is always 6 miles per hour. Ordinarily she completes her circuit at 7:00 am, but yesterday she completed it at 8:00 am. The only difference is that she ran the course counterclockwise rather than clockwise. How long is the course (in miles)? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #527950 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=527950\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Every morning at precisely 6:00 am, Susie begins her jogging circuit of the neighborhood.<BR>\n" );
document.write( " It’s a hilly route with no level stretches.<BR>\n" );
document.write( " Her uphill speed is always 2 miles per hour and her downhill speed is always 6 miles per hour.<BR>\n" );
document.write( " Ordinarily she completes her circuit at 7:00 am, but yesterday she completed it at 8:00 am.<BR>\n" );
document.write( " The only difference is that she ran the course counterclockwise rather than clockwise.<BR>\n" );
document.write( " How long is the course (in miles)?<BR>\n" );
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document.write( "Let x = original up-hill distance, at 2 mph<BR>\n" );
document.write( "Let y = original down-hill distance, at 6 mph<BR>\n" );
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document.write( "When he reverses the the circuit (goes counterclockwise)<BR>\n" );
document.write( "x = down-hill distance, at 6 mph<BR>\n" );
document.write( "y = up-hill distance, at 2 mph<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Write a time equation for each circuit, time = dist/speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%2F2 ALIGN=MIDDLE  ALT=\"x%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%2F6 ALIGN=MIDDLE  ALT=\"y%2F6\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1 hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%2F6 ALIGN=MIDDLE  ALT=\"x%2F6\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%2F2 ALIGN=MIDDLE  ALT=\"y%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 2 hr<BR>\n" );
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document.write( "multiply both equations by 6 to clear the denominators<BR>\n" );
document.write( "3x + y = 6<BR>\n" );
document.write( "x + 3y = 12<BR>\n" );
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document.write( "Multiply the 1st equation by 3, subtract the 2nd equation<BR>\n" );
document.write( "9x + 3y = 18<BR>\n" );
document.write( " x + 3y = 12<BR>\n" );
document.write( "---------------Subtraction eliminates y find x<BR>\n" );
document.write( "8x = 6<BR>\n" );
document.write( "x = 6/8 = .75 mi <BR>\n" );
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document.write( "Find y<BR>\n" );
document.write( ".75 + 3y = 12<BR>\n" );
document.write( "3y = 12 - .75<BR>\n" );
document.write( "3y = 11.25<BR>\n" );
document.write( "y = 11.25/3<BR>\n" );
document.write( "y = 3.75<BR>\n" );
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document.write( "Find the distance of one circuit<BR>\n" );
document.write( ".75 + 3.75 = 4.5 mi is the length of the course </SPAN>\n" );
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