document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=973854>Question 973854</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Simone and Sean are running in a four-mile relay race. After Simone completes the first two miles, Sean runs the second two miles. Sean runs 1 mile per hour slower than Simone. Together they complete the race in 0.9 hours. How fast did each person run? Justify your answer. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #596033 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=596033\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Simone and Sean are running in a four-mile relay race. After Simone completes the first two miles, Sean runs the second two miles. Sean runs 1 mile per hour slower than Simone. Together they complete the race in 0.9 hours. How fast did each person run? <BR>\n" );
document.write( "***<BR>\n" );
document.write( "let x= Sean's speed<BR>\n" );
document.write( "x+1=simon's v  speed<BR>\n" );
document.write( "travel time=distance / speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2Fx%2B2%2F%28x%2B1%29=0.9 ALIGN=MIDDLE  ALT=\"2%2Fx%2B2%2F%28x%2B1%29=0.9\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "lcd: x(x+1)<BR>\n" );
document.write( "2(x+1)+2x=0.9(x^2+x)<BR>\n" );
document.write( "mult. by 10<BR>\n" );
document.write( "20(x+1)+20x=9(x^2+x)<BR>\n" );
document.write( "20x+20+20x=9x^2+9x<BR>\n" );
document.write( "9x^2-31x-20=0<BR>\n" );
document.write( "solve for x by quadratic formula:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a=9, b=-31, c=-20<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2831+%2B-+sqrt%28+31%5E2-4%2A9%2A-20%29%29%2F%282%2A9%29+ ALIGN=MIDDLE  ALT=\"x+=+%2831+%2B-+sqrt%28+31%5E2-4%2A9%2A-20%29%29%2F%282%2A9%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2831+%2B-+sqrt%28+961%2B720%29%29%2F%2818%29+ ALIGN=MIDDLE  ALT=\"x+=+%2831+%2B-+sqrt%28+961%2B720%29%29%2F%2818%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2831+%2B-+sqrt%281681%29%29%2F%2818%29+ ALIGN=MIDDLE  ALT=\"x+=+%2831+%2B-+sqrt%281681%29%29%2F%2818%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2831+%2B-+sqrt%281681%29%29%2F%2818%29+ ALIGN=MIDDLE  ALT=\"x+=+%2831+%2B-+sqrt%281681%29%29%2F%2818%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%2831+%2B41%29%2F%2818%29=72%2F18=4+ ALIGN=MIDDLE  ALT=\"x+=+%2831+%2B41%29%2F%2818%29=72%2F18=4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "How fast did each person run?<BR>\n" );
document.write( "Sean: 4 mph<BR>\n" );
document.write( "Simon: 5 mph<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );