document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=161020>Question 161020</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Extreme hardship. Kim starts to walk 3 mi to school at 7:30 A.M. with a temperature of 0°F. Her brother Bryan starts at 7:45 A.M. on his bicycle, traveling 10 mph faster than Kim. If they get to school at the same time, then how fast is each one traveling? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #118666 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=118666\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Kim starts to walk 3 mi to school at 7:30 A.M. with a temperature of 0°F. Her brother Bryan starts at 7:45 A.M. on his bicycle, traveling 10 mph faster than Kim. If they get to school at the same time, then how fast is each one traveling?<BR>\n" );
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document.write( "Change 15 min to hrs: 15/60 = .25 hrs<BR>\n" );
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document.write( "Let s = K's walking speed<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s+10) = B's biking speed<BR>\n" );
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document.write( "Write a time equation: Time = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=dist%2Fspeed ALIGN=MIDDLE  ALT=\"dist%2Fspeed\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "K's travel time = B's travel time + .25 hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2Fs ALIGN=MIDDLE  ALT=\"3%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F%28%28s%2B10%29%29 ALIGN=MIDDLE  ALT=\"3%2F%28%28s%2B10%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > + .25<BR>\n" );
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document.write( "Multiply equation by t(t+10) to get rid of the denominator, results<BR>\n" );
document.write( "3(s+10) = 3s + .25(s(s+10)<BR>\n" );
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document.write( "3s + 30 = 3s + .25s^2 + 2.5s<BR>\n" );
document.write( "Arrange as a quadratic equation on the right<BR>\n" );
document.write( "0 = .25s^2 + 2.5s + 3s - 3s - 30 <BR>\n" );
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document.write( ".25s^2 + 2.5s - 30 = 0<BR>\n" );
document.write( "Get rid of those decimals, mult equation by 4, results<BR>\n" );
document.write( "s^2 + 10s - 120 = 0<BR>\n" );
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document.write( "Use the quadratic formula to solve for s:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"s+=+%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( "In this equation a=1, b=10, c=-120<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s+=+%28-10+%2B-+sqrt%2810%5E2+-+4%2A1%2A-120+%29%29%2F%282%2A1%29+ ALIGN=MIDDLE  ALT=\"s+=+%28-10+%2B-+sqrt%2810%5E2+-+4%2A1%2A-120+%29%29%2F%282%2A1%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s+=+%28-10+%2B-+sqrt%28100+%2B+480+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"s+=+%28-10+%2B-+sqrt%28100+%2B+480+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "solve this you should get a postive solution of:<BR>\n" );
document.write( "s = 7.05 mph is K's walking speed<BR>\n" );
document.write( "then<BR>\n" );
document.write( "7.05 + 10 = 17.05 mph is B's biking speed <BR>\n" );
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document.write( "Confirm this by finding the time of each<BR>\n" );
document.write( "3/7.05 = .425 hrs or 25.5 min<BR>\n" );
document.write( "3/17.05 = .176 hrs or 10.6 min<BR>\n" );
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document.write( "Difference ~ 15 min <BR>\n" );
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