document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=843383>Question 843383</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A girl rows 11 km downstream in 2 h. Her return trip takes 3 h. How fast can she row in still water. in km/h? <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #508077 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=508077\">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;\" > = her speed in still water in km/hr<BR>\n" );
document.write( "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 speed of the current in km/hr<BR>\n" );
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document.write( "Equation for rowing downstream:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+11+=+%28+s+%2B+c+%29%2A2+ ALIGN=MIDDLE  ALT=\"+11+=+%28+s+%2B+c+%29%2A2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Equation for rowing upstream:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+11+=+%28+s+-+c+%29%2A3+ ALIGN=MIDDLE  ALT=\"+11+=+%28+s+-+c+%29%2A3+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----------------------------<BR>\n" );
document.write( "This is 2 equations and 2 unknowns <BR>\n" );
document.write( "so it's solvable<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+11+=+2s+%2B+2c+ ALIGN=MIDDLE  ALT=\"+11+=+2s+%2B+2c+\"   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=+11+=+3s+-+3c+ ALIGN=MIDDLE  ALT=\"+11+=+3s+-+3c+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----------------------<BR>\n" );
document.write( "Multiply both sides of (1) 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( "both sides of (2) 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( "Then add the equations<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6s+%2B+6c+=+33+ ALIGN=MIDDLE  ALT=\"+6s+%2B+6c+=+33+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6s+-+6c+=+22+ ALIGN=MIDDLE  ALT=\"+6s+-+6c+=+22+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12s+=+55+ ALIGN=MIDDLE  ALT=\"+12s+=+55+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+4.5833+ ALIGN=MIDDLE  ALT=\"+s+=+4.5833+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "She can row 4.5833 km/hr in still water<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2s+%2B+2c+=+11+ ALIGN=MIDDLE  ALT=\"+2s+%2B+2c+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2A%2855%2F12%29+%2B+2c+=+11+ ALIGN=MIDDLE  ALT=\"+2%2A%2855%2F12%29+%2B+2c+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+55%2F6+%2B+2c+=+11+ ALIGN=MIDDLE  ALT=\"+55%2F6+%2B+2c+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2c+=+66%2F6+-+55%2F6+ ALIGN=MIDDLE  ALT=\"+2c+=+66%2F6+-+55%2F6+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2c+=+11%2F6+ ALIGN=MIDDLE  ALT=\"+2c+=+11%2F6+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+11%2F12+ ALIGN=MIDDLE  ALT=\"+c+=+11%2F12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+.9167+ ALIGN=MIDDLE  ALT=\"+c+=+.9167+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3s+-+3c+=+11+ ALIGN=MIDDLE  ALT=\"+3s+-+3c+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3%2A%2855%2F12%29+-+3%2A%2811%2F12%29+=+11+ ALIGN=MIDDLE  ALT=\"+3%2A%2855%2F12%29+-+3%2A%2811%2F12%29+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3%2A55+-+3%2A11+=+11%2A12+ ALIGN=MIDDLE  ALT=\"+3%2A55+-+3%2A11+=+11%2A12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+3%2A5+-+3+=+12+ ALIGN=MIDDLE  ALT=\"+3%2A5+-+3+=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+-+3+=+12+ ALIGN=MIDDLE  ALT=\"+15+-+3+=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12+=+12+ ALIGN=MIDDLE  ALT=\"+12+=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2s+%2B+2c+=+11+ ALIGN=MIDDLE  ALT=\"+2s+%2B+2c+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2A%2855%2F12%29+%2B+2%2A%2811%2F12%29+=+11+ ALIGN=MIDDLE  ALT=\"+2%2A%2855%2F12%29+%2B+2%2A%2811%2F12%29+=+11+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2A55+%2B+2%2A11+=+11%2A12+ ALIGN=MIDDLE  ALT=\"+2%2A55+%2B+2%2A11+=+11%2A12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2A5+%2B+2+=+12+ ALIGN=MIDDLE  ALT=\"+2%2A5+%2B+2+=+12+\"   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+%2B+2++=+12+ ALIGN=MIDDLE  ALT=\"+10+%2B+2++=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+12+=+12+ ALIGN=MIDDLE  ALT=\"+12+=+12+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
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document.write( "</TD></TR></TABLE>\n" );