document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=445757>Question 445757</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A  motorboat  takes  3  hrs  to  travel  144  km  going  upstream  the  return  trip  takes  2  hrs  going  downstream  what  is  the   rate  of  the  boat  in  still  water  and  what  is  the  rate   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 #306985 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=306985\">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;\" > = the rate of the current<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b ALIGN=MIDDLE  ALT=\"b\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the speed of the boat in still water<BR>\n" );
document.write( "given:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d=+144+km+ ALIGN=MIDDLE  ALT=\"+d=+144+km+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "time going upstream: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t%5B1%5D+=+3 ALIGN=MIDDLE  ALT=\"+t%5B1%5D+=+3\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "time going downstream: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t%5B2%5D+=+2+ ALIGN=MIDDLE  ALT=\"+t%5B2%5D+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "The equation going upstream:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+%28+b+-+c+%29%2At%5B1%5D+ ALIGN=MIDDLE  ALT=\"+d+=+%28+b+-+c+%29%2At%5B1%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=+144+=+%28+b+-+c+%29%2A3+ ALIGN=MIDDLE  ALT=\"+144+=+%28+b+-+c+%29%2A3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The equation going downstream:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+%28+b+%2B+c+%29%2At%5B2%5D+ ALIGN=MIDDLE  ALT=\"+d+=+%28+b+%2B+c+%29%2At%5B2%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=+144+=+%28+b+%2B+c+%29%2A2+ ALIGN=MIDDLE  ALT=\"+144+=+%28+b+%2B+c+%29%2A2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "There are 2 equations and 2 unknowns, so<BR>\n" );
document.write( "it should be solvable<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+144+=+%28+b+-+c+%29%2A3+ ALIGN=MIDDLE  ALT=\"+144+=+%28+b+-+c+%29%2A3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3b+-+3c+=+144+ ALIGN=MIDDLE  ALT=\"+3b+-+3c+=+144+\"   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=+144+=+%28+b+%2B+c+%29%2A2+ ALIGN=MIDDLE  ALT=\"+144+=+%28+b+%2B+c+%29%2A2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2b+%2B+2c+=+144+ ALIGN=MIDDLE  ALT=\"+2b+%2B+2c+=+144+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply both sides of (1) by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2 ALIGN=MIDDLE  ALT=\"2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and both sides of (2) by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3 ALIGN=MIDDLE  ALT=\"3\"   DISABLED_style= \"max-width:90%; height:auto;\" > and<BR>\n" );
document.write( "subtract (1) from (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6b+%2B+6c+=+432+ ALIGN=MIDDLE  ALT=\"+6b+%2B+6c+=+432+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-6b+%2B+6c+=+-288+ ALIGN=MIDDLE  ALT=\"+-6b+%2B+6c+=+-288+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12c+=+144+ ALIGN=MIDDLE  ALT=\"+12c+=+144+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+12+ ALIGN=MIDDLE  ALT=\"+c+=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" > km/hr<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2b+%2B+2c+=+144+ ALIGN=MIDDLE  ALT=\"+2b+%2B+2c+=+144+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2b+%2B+2%2A12+=+144+ ALIGN=MIDDLE  ALT=\"+2b+%2B+2%2A12+=+144+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2b+=+144+-+24+ ALIGN=MIDDLE  ALT=\"+2b+=+144+-+24+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2b+=+120+ ALIGN=MIDDLE  ALT=\"+2b+=+120+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+60+ ALIGN=MIDDLE  ALT=\"+b+=+60+\"   DISABLED_style= \"max-width:90%; height:auto;\" > km/hr<BR>\n" );
document.write( "12 km/hr is the rate of the current<BR>\n" );
document.write( "60 km/hr is the speed of the boat in still water </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );