document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=937773>Question 937773</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A cruise ship left Port 37 and traveled south. A submarine left nine hours later traveling 18 mph faster in an effort to catch up to it. After five hours the submarine finally caught up. Find the submarine's average speed. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #571187 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=571187\">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=+s+ ALIGN=MIDDLE  ALT=\"+s+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the speed of the cruise ship in mi/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9s+ ALIGN=MIDDLE  ALT=\"+9s+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the cruise ship's head start in miles<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+%2B+18+ ALIGN=MIDDLE  ALT=\"+s+%2B+18+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the speed of the submarine in mi/hr<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 in miles that the submarine travels<BR>\n" );
document.write( "until it catches the cruise ship<BR>\n" );
document.write( "--------------------------<BR>\n" );
document.write( "Start measuring time in hrs when submarine leaves<BR>\n" );
document.write( "Cruise ship's equation:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+-+9s+=+s%2A5+ ALIGN=MIDDLE  ALT=\"+d+-+9s+=+s%2A5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Submarine's equation:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+%28+s+%2B+18+%29%2A5+ ALIGN=MIDDLE  ALT=\"+d+=+%28+s+%2B+18+%29%2A5+\"   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=+%28+s+%2B+18+%29%2A5+-+9s+=+s%2A5+ ALIGN=MIDDLE  ALT=\"+%28+s+%2B+18+%29%2A5+-+9s+=+s%2A5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+5s+%2B+90+-+9s+=+5s+ ALIGN=MIDDLE  ALT=\"+5s+%2B+90+-+9s+=+5s+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+9s+=+90+ ALIGN=MIDDLE  ALT=\"+9s+=+90+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+10+ ALIGN=MIDDLE  ALT=\"+s+=+10+\"   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=+s+%2B+18+=+10+%2B+18+ ALIGN=MIDDLE  ALT=\"+s+%2B+18+=+10+%2B+18+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+%2B+18+=+28+ ALIGN=MIDDLE  ALT=\"+s+%2B+18+=+28+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The submarine's average speed was 28 mi/hr<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+=+%28+10+%2B+18+%29%2A5+ ALIGN=MIDDLE  ALT=\"+d+=+%28+10+%2B+18+%29%2A5+\"   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+=+28%2A5+ ALIGN=MIDDLE  ALT=\"+d+=+28%2A5+\"   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+=+140+ ALIGN=MIDDLE  ALT=\"+d+=+140+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+-+9s+=+s%2A5+ ALIGN=MIDDLE  ALT=\"+d+-+9s+=+s%2A5+\"   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+-+9%2A10+=+10%2A5+ ALIGN=MIDDLE  ALT=\"+d+-+9%2A10+=+10%2A5+\"   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+=+90+%2B+50+ ALIGN=MIDDLE  ALT=\"+d+=+90+%2B+50+\"   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+=+140+ ALIGN=MIDDLE  ALT=\"+d+=+140+\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "OK\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );