document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1014272>Question 1014272</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorist averaged 670 miles in 12 hours. Before 4 pm, he averaged 60 mph and after 4 pm he averaged 50 mph. At what time did he begin his trip and at what time did he end it? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #630601 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=630601\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 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 in miles he covered before 4 PM<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+670+-+d+ ALIGN=MIDDLE  ALT=\"+670+-+d+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = distance in miles he covered after 4 PM<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = time of trip before 4 PM<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12+-+t+ ALIGN=MIDDLE  ALT=\"+12+-+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = time of trip after 4 PM<BR>\n" );
document.write( "--------------------------------<BR>\n" );
document.write( "Equation before 4 PM:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+60t+ ALIGN=MIDDLE  ALT=\"+d+=+60t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Equation after 4 PM:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+670+-+d+=+50%2A%28+12+-+t+%29+ ALIGN=MIDDLE  ALT=\"+670+-+d+=+50%2A%28+12+-+t+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+670+-60t+=+50%2A%28+12+-+t+%29+ ALIGN=MIDDLE  ALT=\"+670+-60t+=+50%2A%28+12+-+t+%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=+670+-60t+=+600+-+50t+ ALIGN=MIDDLE  ALT=\"+670+-60t+=+600+-+50t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10t+=+670+-+600+ ALIGN=MIDDLE  ALT=\"+10t+=+670+-+600+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10t+=+70+ ALIGN=MIDDLE  ALT=\"+10t+=+70+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+7+ ALIGN=MIDDLE  ALT=\"+t+=+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12+-+t+=+5+ ALIGN=MIDDLE  ALT=\"+12+-+t+=+5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "7 hrs before 4 PM is 9AM<BR>\n" );
document.write( "5 hrs after 4 PM is 9 PM<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "He began at 9AM and ended at 9 PM<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+=+60t+ ALIGN=MIDDLE  ALT=\"+d+=+60t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+60%2A7+ ALIGN=MIDDLE  ALT=\"+d+=+60%2A7+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+420+ ALIGN=MIDDLE  ALT=\"+d+=+420+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+670+-+d+=+50%2A%28+12+-+t+%29+ ALIGN=MIDDLE  ALT=\"+670+-+d+=+50%2A%28+12+-+t+%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=+670+-+d+=+50%2A%28+12+-7+%29+ ALIGN=MIDDLE  ALT=\"+670+-+d+=+50%2A%28+12+-7+%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=+670+-+d+=+250+ ALIGN=MIDDLE  ALT=\"+670+-+d+=+250+\"   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+=+670+-+250+ ALIGN=MIDDLE  ALT=\"+d+=+670+-+250+\"   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+=+420+ ALIGN=MIDDLE  ALT=\"+d+=+420+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );