document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=789186>Question 789186</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve this word problem? Alan and Dave leave from the same point driving in opposite directions, Alan driving at 55 miles per hour and Dave at 65 mph. Alan has a one-hour head start. How long will they be able to talk on their car phones if the phones have a 250-mile range.\r<BR>\n" );
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document.write( "Test on Tuesday. Thanks for all your help.<BR>\n" );
document.write( "Michael Armani </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #478760 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=478760\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You need an equation for Alan and an equation for Dave<BR>\n" );
document.write( "You want to know when they are <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+ ALIGN=MIDDLE  ALT=\"+250+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi apart<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "First, you want to know how much of a head start Alan has<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5B1%5D+ ALIGN=MIDDLE  ALT=\"+d%5B1%5D+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = his head start<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5B1%5D+=+55%2A1+ ALIGN=MIDDLE  ALT=\"+d%5B1%5D+=+55%2A1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%5B1%5D+=+55+ ALIGN=MIDDLE  ALT=\"+d%5B1%5D+=+55+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "---------------<BR>\n" );
document.write( "Start a stopwatch when Dave leaves<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 on stopwatch when they are <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+ ALIGN=MIDDLE  ALT=\"+250+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi apart<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 that Dave has traveled <BR>\n" );
document.write( "when they are <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+ ALIGN=MIDDLE  ALT=\"+250+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi apart<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+-+d+ ALIGN=MIDDLE  ALT=\"+250+-+d+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = Alan's distance from starting point when <BR>\n" );
document.write( "they are <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+ ALIGN=MIDDLE  ALT=\"+250+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi apart<BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "Alan's equation:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+-+d+-+55+=+55t+ ALIGN=MIDDLE  ALT=\"+250+-+d+-+55+=+55t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "( note that I had to subtract his head start )<BR>\n" );
document.write( "Dave's equation:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+65t+ ALIGN=MIDDLE  ALT=\"+d+=+65t+\"   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=+250+-+65t+-+55+=+55t+ ALIGN=MIDDLE  ALT=\"+250+-+65t+-+55+=+55t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+120t+=+195+ ALIGN=MIDDLE  ALT=\"+120t+=+195+\"   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+=+1.625+ ALIGN=MIDDLE  ALT=\"+t+=+1.625+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+.625%2A60+=+37.5+ ALIGN=MIDDLE  ALT=\"+.625%2A60+=+37.5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "They can talk for 1 hr 37 min 30 sec<BR>\n" );
document.write( "-------------------<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+65t+ ALIGN=MIDDLE  ALT=\"+d+=+65t+\"   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+=+65%2A1.625+ ALIGN=MIDDLE  ALT=\"+d+=+65%2A1.625+\"   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+=+105.625+ ALIGN=MIDDLE  ALT=\"+d+=+105.625+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+-+d+-+55+=+55t+ ALIGN=MIDDLE  ALT=\"+250+-+d+-+55+=+55t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+250+-+d+-+55+=+55%2A1.625+ ALIGN=MIDDLE  ALT=\"+250+-+d+-+55+=+55%2A1.625+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+195+-+d+=+89.375+ ALIGN=MIDDLE  ALT=\"+195+-+d+=+89.375+\"   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+=+195+-+89.375+ ALIGN=MIDDLE  ALT=\"+d+=+195+-+89.375+\"   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+=+105.625+ ALIGN=MIDDLE  ALT=\"+d+=+105.625+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK \r<BR>\n" );
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document.write( " </SPAN>\n" );
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