document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=319437>Question 319437</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In still water a tugboat can travel 15 miles per hour. It travels 36 miles upstream and then 36 miles downstream in a total time of 5 hours. Find the speed of the current. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #228740 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=228740\">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=c ALIGN=MIDDLE  ALT=\"c\"   DISABLED_style= \"max-width:90%; height:auto;\" > = speed of current<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15+-+c ALIGN=MIDDLE  ALT=\"15+-+c\"   DISABLED_style= \"max-width:90%; height:auto;\" > = speed going upstream<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15+%2B+c ALIGN=MIDDLE  ALT=\"15+%2B+c\"   DISABLED_style= \"max-width:90%; height:auto;\" > = speed going downstream<BR>\n" );
document.write( "(1)<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=36+=+%2815+-+c%29%2At%5Bu%5D ALIGN=MIDDLE  ALT=\"36+=+%2815+-+c%29%2At%5Bu%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=36+=+%2815+%2B+c%29%2At%5Bd%5D ALIGN=MIDDLE  ALT=\"36+=+%2815+%2B+c%29%2At%5Bd%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(3) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+5 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "----------------------------<BR>\n" );
document.write( "(1)<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=36+=+%2815+-+c%29%2At%5Bu%5D ALIGN=MIDDLE  ALT=\"36+=+%2815+-+c%29%2At%5Bu%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+=+36%2F%2815+-+c%29 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+=+36%2F%2815+-+c%29\"   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=36+=+%2815+%2B+c%29%2At%5Bd%5D ALIGN=MIDDLE  ALT=\"36+=+%2815+%2B+c%29%2At%5Bd%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bd%5D+=+36%2F%2815+%2B+c%29 ALIGN=MIDDLE  ALT=\"t%5Bd%5D+=+36%2F%2815+%2B+c%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Adding:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F%2815+-+c%29+%2B+1%2F%2815+%2B+c%29%29 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F%2815+-+c%29+%2B+1%2F%2815+%2B+c%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5+=+36%2A%281%2F%2815+-+c%29+%2B+1%2F%2815+%2B+c%29%29 ALIGN=MIDDLE  ALT=\"5+=+36%2A%281%2F%2815+-+c%29+%2B+1%2F%2815+%2B+c%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2815+-+c%29%2815+%2B+c%29 ALIGN=MIDDLE  ALT=\"%2815+-+c%29%2815+%2B+c%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2A%28225+-+c%5E2%29+=+36%2A%2815+%2B+c+%2B+15+-+c%29 ALIGN=MIDDLE  ALT=\"5%2A%28225+-+c%5E2%29+=+36%2A%2815+%2B+c+%2B+15+-+c%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1125+-+5c%5E2+=+36%2A30 ALIGN=MIDDLE  ALT=\"1125+-+5c%5E2+=+36%2A30\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5c%5E2+=+1125+-+1080 ALIGN=MIDDLE  ALT=\"5c%5E2+=+1125+-+1080\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5c%5E2+=+45 ALIGN=MIDDLE  ALT=\"5c%5E2+=+45\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c%5E2+=+9 ALIGN=MIDDLE  ALT=\"c%5E2+=+9\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c+=+3 ALIGN=MIDDLE  ALT=\"c+=+3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The current is 3 mi/hr<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F%2815+-+c%29+%2B+1%2F%2815+%2B+c%29%29 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F%2815+-+c%29+%2B+1%2F%2815+%2B+c%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F%2815+-+3%29+%2B+1%2F%2815+%2B+3%29%29 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F%2815+-+3%29+%2B+1%2F%2815+%2B+3%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F12+%2B+1%2F18%29 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+36%2A%281%2F12+%2B+1%2F18%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+36%2F12+%2B+36%2F18 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+36%2F12+%2B+36%2F18\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+%2B+t%5Bd%5D+=+3+%2B+2 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+%2B+t%5Bd%5D+=+3+%2B+2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );