document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=894437>Question 894437</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat travels 220km in 4 hours going upstream. It travels <BR>\n" );
document.write( "284km going downstream in the same amount of time. 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 #542053 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=542053\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> r = rate of boat if c=0<BR>\n" );
document.write( "t = time going upstream, 4 hour<BR>\n" );
document.write( "u = distance upstream, 220 km<BR>\n" );
document.write( "b = distance going back downstream, 284 km<BR>\n" );
document.write( "c = rate of the current\r<BR>\n" );
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document.write( "________________rate__________time________distance<BR>\n" );
document.write( "upstream________r-c____________t__________u<BR>\n" );
document.write( "downstream______r+c____________t__________b\r<BR>\n" );
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document.write( "The unknown variables are r and c.<BR>\n" );
document.write( "RT=D if the uniform rates travel formula for rate, time, distance.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28r-c%29t=u ALIGN=MIDDLE  ALT=\"%28r-c%29t=u\"   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=%28r%2Bc%29t=b ALIGN=MIDDLE  ALT=\"%28r%2Bc%29t=b\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=rt-ct=u ALIGN=MIDDLE  ALT=\"rt-ct=u\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=rt%2Bct=b ALIGN=MIDDLE  ALT=\"rt%2Bct=b\"   DISABLED_style= \"max-width:90%; height:auto;\" >, the system; perfectly ready for Elimination Method for each variable.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=rt-ct%2Brt%2Bct=u%2Bb ALIGN=MIDDLE  ALT=\"rt-ct%2Brt%2Bct=u%2Bb\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2rt=u%2Bb ALIGN=MIDDLE  ALT=\"2rt=u%2Bb\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28r=%28u%2Bb%29%2F%282t%29%29 ALIGN=MIDDLE  ALT=\"highlight%28r=%28u%2Bb%29%2F%282t%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=rt-ct-%28rt%2Bct%29=u-b ALIGN=MIDDLE  ALT=\"rt-ct-%28rt%2Bct%29=u-b\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=rt-ct-rt-ct=u-b ALIGN=MIDDLE  ALT=\"rt-ct-rt-ct=u-b\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-2ct=u-b ALIGN=MIDDLE  ALT=\"-2ct=u-b\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and you know that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=u-b ALIGN=MIDDLE  ALT=\"u-b\"   DISABLED_style= \"max-width:90%; height:auto;\" > is a negative number, but you will divide both sides 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( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c=%28u-b%29%2F%28-2t%29 ALIGN=MIDDLE  ALT=\"c=%28u-b%29%2F%28-2t%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28c=%28b-u%29%2F%282t%29%29 ALIGN=MIDDLE  ALT=\"highlight%28c=%28b-u%29%2F%282t%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Look above at the variable assignments, and substitute what was given to compute c and r.  You can use the same formulas here in case you find another example travel problem that is in the same general form as this one. </SPAN>\n" );
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