document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=300475>Question 300475</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A man leaves for work at the same time each morning. If his travel speed averages 30 miles per hour, he will be 18 minutes late. If his travel speed averages 45 miles per hour, he will arrive 8 minutes early. What average travel speed (in miles per hour) will put him at work precisely on time? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #215680 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=215680\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A man leaves for work at the same time each morning.<BR>\n" );
document.write( "If his travel speed averages 30 miles per hour, he will be 18 minutes late.<BR>\n" );
document.write( " If his travel speed averages 45 miles per hour, he will arrive 8 minutes early.<BR>\n" );
document.write( " What average travel speed (in miles per hour) will put him at work precisely on time?<BR>\n" );
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document.write( "Let s = av speed to arrive on time<BR>\n" );
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document.write( "let d = distance<BR>\n" );
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document.write( "Write two time equations; time = dist/speed<BR>\n" );
document.write( "The late equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F30 ALIGN=MIDDLE  ALT=\"d%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2Fs ALIGN=MIDDLE  ALT=\"d%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=18%2F60 ALIGN=MIDDLE  ALT=\"18%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The early equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2Fs ALIGN=MIDDLE  ALT=\"d%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F45 ALIGN=MIDDLE  ALT=\"d%2F45\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8%2F60 ALIGN=MIDDLE  ALT=\"8%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( ":<BR>\n" );
document.write( "clear the denominators, multiply both equations by 180s and arrange like this:<BR>\n" );
document.write( " 6ds - 180d = 54s<BR>\n" );
document.write( "-4ds + 180d = 24s<BR>\n" );
document.write( "--------------------addition eliminates 180d<BR>\n" );
document.write( "2ds = 78s<BR>\n" );
document.write( "divide both sides by s<BR>\n" );
document.write( "2d = 78<BR>\n" );
document.write( "d = 39 mi is the distance<BR>\n" );
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document.write( "Find s<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2Fs ALIGN=MIDDLE  ALT=\"39%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2F45 ALIGN=MIDDLE  ALT=\"39%2F45\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8%2F60 ALIGN=MIDDLE  ALT=\"8%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2Fs ALIGN=MIDDLE  ALT=\"39%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2F45 ALIGN=MIDDLE  ALT=\"39%2F45\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=8%2F60 ALIGN=MIDDLE  ALT=\"8%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "using a calc<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2Fs ALIGN=MIDDLE  ALT=\"39%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = .867 + .133<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2Fs ALIGN=MIDDLE  ALT=\"39%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "s = 39 mph to arrive on time (in 1 hr)<BR>\n" );
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document.write( "Check solution using the late equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2F30 ALIGN=MIDDLE  ALT=\"d%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%2Fs ALIGN=MIDDLE  ALT=\"d%2Fs\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=18%2F60 ALIGN=MIDDLE  ALT=\"18%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2F30 ALIGN=MIDDLE  ALT=\"39%2F30\"   DISABLED_style= \"max-width:90%; height:auto;\" > - <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=39%2F39 ALIGN=MIDDLE  ALT=\"39%2F39\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=18%2F60 ALIGN=MIDDLE  ALT=\"18%2F60\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "using a calc<BR>\n" );
document.write( "1.3 - 1 = .3; confirms our solution 39 miles and 39 mph\r<BR>\n" );
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document.write( " </SPAN>\n" );
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