document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=640276>Question 640276</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Tina is going for a walk, traveling at 4 mph. After 30 minutes, David leaves on his bike to try to catch up; he is traveling at 13 mph. If he follows the same route, how long will it take him to catch up (in minutes)? How far will they both have traveled? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #403142 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=403142\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Tina's head start is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4%2A.5+=+2+ ALIGN=MIDDLE  ALT=\"+4%2A.5+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "Start a stopwatch when David leaves<BR>\n" );
document.write( "They will both travel for the same amount<BR>\n" );
document.write( "of time = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t ALIGN=MIDDLE  ALT=\"t\"   DISABLED_style= \"max-width:90%; height:auto;\" > in hours<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+ ALIGN=MIDDLE  ALT=\"+d+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = distance David travels in miles <BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "Tina's equation:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+-+2+=+4t+ ALIGN=MIDDLE  ALT=\"+d+-+2+=+4t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "David's equation:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+13t+ ALIGN=MIDDLE  ALT=\"+d+=+13t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "Substitute (2) into (1)<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+13t+-+2+=+4t+ ALIGN=MIDDLE  ALT=\"+13t+-+2+=+4t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9t+=+2+ ALIGN=MIDDLE  ALT=\"+9t+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+2%2F9+ ALIGN=MIDDLE  ALT=\"+t+=+2%2F9+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Convert to minutes and seconds<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%282%2F9%29%2A60+=+40%2F3+ ALIGN=MIDDLE  ALT=\"+%282%2F9%29%2A60+=+40%2F3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+40%2F3+=+13+%2B+1%2F3+ ALIGN=MIDDLE  ALT=\"+40%2F3+=+13+%2B+1%2F3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%281%2F3%29%2A60+=+20+ ALIGN=MIDDLE  ALT=\"+%281%2F3%29%2A60+=+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "David catches up in 13 min 20 sec<BR>\n" );
document.write( "--------------------------<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+13%2A%282%2F9%29+ ALIGN=MIDDLE  ALT=\"+d+=+13%2A%282%2F9%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+26%2F9+ ALIGN=MIDDLE  ALT=\"+d+=+26%2F9+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+2.889+ ALIGN=MIDDLE  ALT=\"+d+=+2.889+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+-+2+=+.889+ ALIGN=MIDDLE  ALT=\"+d+-+2+=+.889+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "David travels 2.889 mi<BR>\n" );
document.write( "Tina also travels 2.889 mi in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+30+%2B+13+ ALIGN=MIDDLE  ALT=\"+30+%2B+13+\"   DISABLED_style= \"max-width:90%; height:auto;\" > min and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+20+ ALIGN=MIDDLE  ALT=\"+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" > sec<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+-+2+=+4t+ ALIGN=MIDDLE  ALT=\"+d+-+2+=+4t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+26%2F9+-+2+=+4%2A%282%2F9%29+ ALIGN=MIDDLE  ALT=\"+26%2F9+-+2+=+4%2A%282%2F9%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+26+-+18+=+8+ ALIGN=MIDDLE  ALT=\"+26+-+18+=+8+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+26+=+26+ ALIGN=MIDDLE  ALT=\"+26+=+26+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );