document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=180585>Question 180585</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat went 10 miles upstream in 1 hour. The return trip took only 30 minutes. Assume that the \"water speed\" and the current speed were constant during both parts of the trip. Find the water speed of the boat and the current speed. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #135382 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=135382\">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=r%5Bb%5D ALIGN=MIDDLE  ALT=\"r%5Bb%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >= the speed of the boat in still water<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Bc%5D ALIGN=MIDDLE  ALT=\"r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >= the speed of the current<BR>\n" );
document.write( "For the trip upstream:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Bu%5D+=+r%5Bu%5D%2At%5Bu%5D ALIGN=MIDDLE  ALT=\"d%5Bu%5D+=+r%5Bu%5D%2At%5Bu%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "For the trip downstream:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Bd%5D+=+r%5Bd%5D%2At%5Bd%5D ALIGN=MIDDLE  ALT=\"d%5Bd%5D+=+r%5Bd%5D%2At%5Bd%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "given:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Bu%5D+=+10 ALIGN=MIDDLE  ALT=\"d%5Bu%5D+=+10\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Bd%5D+=+10 ALIGN=MIDDLE  ALT=\"d%5Bd%5D+=+10\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bu%5D+=+1 ALIGN=MIDDLE  ALT=\"t%5Bu%5D+=+1\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t%5Bd%5D+=+.5 ALIGN=MIDDLE  ALT=\"t%5Bd%5D+=+.5\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
document.write( "upstream:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Bu%5D+=+r%5Bb%5D+-+r%5Bc%5D ALIGN=MIDDLE  ALT=\"r%5Bu%5D+=+r%5Bb%5D+-+r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Bd%5D+=+r%5Bb%5D+%2B+r%5Bc%5D ALIGN=MIDDLE  ALT=\"r%5Bd%5D+=+r%5Bb%5D+%2B+r%5Bc%5D\"   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=d%5Bu%5D+=+r%5Bu%5D%2At%5Bu%5D ALIGN=MIDDLE  ALT=\"d%5Bu%5D+=+r%5Bu%5D%2At%5Bu%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+r%5Bu%5D%2A1 ALIGN=MIDDLE  ALT=\"10+=+r%5Bu%5D%2A1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+%28r%5Bb%5D+-+r%5Bc%5D%29%2A1 ALIGN=MIDDLE  ALT=\"10+=+%28r%5Bb%5D+-+r%5Bc%5D%29%2A1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+r%5Bb%5D+-+r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+r%5Bb%5D+-+r%5Bc%5D\"   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=d%5Bd%5D+=+r%5Bd%5D%2At%5Bd%5D ALIGN=MIDDLE  ALT=\"d%5Bd%5D+=+r%5Bd%5D%2At%5Bd%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=10+=+r%5Bd%5D%2A.5 ALIGN=MIDDLE  ALT=\"10+=+r%5Bd%5D%2A.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+%28r%5Bb%5D+%2B+r%5Bc%5D%29%2A.5 ALIGN=MIDDLE  ALT=\"10+=+%28r%5Bb%5D+%2B+r%5Bc%5D%29%2A.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+.5r%5Bb%5D+%2B+.5r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+.5r%5Bb%5D+%2B+.5r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------------<BR>\n" );
document.write( "Subtract (2) from (1)<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+r%5Bb%5D+-+r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+r%5Bb%5D+-+r%5Bc%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=-10+=+-.5r%5Bb%5D+-+.5r%5Bc%5D ALIGN=MIDDLE  ALT=\"-10+=+-.5r%5Bb%5D+-+.5r%5Bc%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=0+=+.5r%5Bb%5D+-+1.5r%5Bc%5D ALIGN=MIDDLE  ALT=\"0+=+.5r%5Bb%5D+-+1.5r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1.5r%5Bc%5D+=+.5r%5Bb%5D ALIGN=MIDDLE  ALT=\"1.5r%5Bc%5D+=+.5r%5Bb%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3r%5Bc%5D+=+r%5Bb%5D ALIGN=MIDDLE  ALT=\"3r%5Bc%5D+=+r%5Bb%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Now I can rewrite (1)<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+r%5Bb%5D+-+r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+r%5Bb%5D+-+r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+3r%5Bc%5D+-+r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+3r%5Bc%5D+-+r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+2r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+2r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Bc%5D+=+5 ALIGN=MIDDLE  ALT=\"r%5Bc%5D+=+5\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "and, since<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+r%5Bb%5D+-+r%5Bc%5D ALIGN=MIDDLE  ALT=\"10+=+r%5Bb%5D+-+r%5Bc%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+r%5Bb%5D+-+5 ALIGN=MIDDLE  ALT=\"10+=+r%5Bb%5D+-+5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Bb%5D+=+15 ALIGN=MIDDLE  ALT=\"r%5Bb%5D+=+15\"   DISABLED_style= \"max-width:90%; height:auto;\" > mi/hr<BR>\n" );
document.write( "The speed of ther boat in still water is 15 mi/hr<BR>\n" );
document.write( "The speed of the current is 5 mi/hr<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+%28r%5Bb%5D+%2B+r%5Bc%5D%29%2A.5 ALIGN=MIDDLE  ALT=\"10+=+%28r%5Bb%5D+%2B+r%5Bc%5D%29%2A.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+%2815+%2B+5%29%2A.5 ALIGN=MIDDLE  ALT=\"10+=+%2815+%2B+5%29%2A.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+20%2A.5 ALIGN=MIDDLE  ALT=\"10+=+20%2A.5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=10+=+10 ALIGN=MIDDLE  ALT=\"10+=+10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "   </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );