document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=880566>Question 880566</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Don williams uses his small motorboat to go 5 miles upstream to his favorite fishing spot. Against the current, the trip takes 5/12 hour. With the current the trip takes 1/4 hour. How fast can the boat travel in still water. What is the speed of the current.<BR>\n" );
document.write( "In still water the boats speed is       mph<BR>\n" );
document.write( "The speed of the current is        mph </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #531590 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=531590\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Don williams uses his small motorboat to go 5 miles upstream to his favorite fishing spot.<BR>\n" );
document.write( " Against the current, the trip takes 5/12 hour.<BR>\n" );
document.write( " With the current the trip takes 1/4 hour.<BR>\n" );
document.write( " How fast can the boat travel in still water.<BR>\n" );
document.write( " What is the speed of the current.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "let s = speed in still water<BR>\n" );
document.write( "let c = rate of the current<BR>\n" );
document.write( "then<BR>\n" );
document.write( "(s-c) = effective speed up-stream<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(s+c) = effective speed down-stream<BR>\n" );
document.write( ":<BR>\n" );
document.write( "Write a distance equation for each way; dist = time * speed<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F12 ALIGN=MIDDLE  ALT=\"5%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" >(s-c) = 5<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" >(s+c) = 5<BR>\n" );
document.write( "Get rid of those annoying fractions, mult the 1st eq by 12, the 2n by 4<BR>\n" );
document.write( "5(s-c) = 60<BR>\n" );
document.write( "s + c = 20<BR>\n" );
document.write( ":<BR>\n" );
document.write( "5s - 5c = 60<BR>\n" );
document.write( "simplify, divide by5, add to the 2nd equation<BR>\n" );
document.write( "s - c = 12<BR>\n" );
document.write( "s + c = 20<BR>\n" );
document.write( "--------------adding eliminates c, find s<BR>\n" );
document.write( "2s = 32<BR>\n" );
document.write( "s = 16 mph is the boat speed in still water<BR>\n" );
document.write( ":<BR>\n" );
document.write( "find the speed of the current<BR>\n" );
document.write( "16 + c = 20<BR>\n" );
document.write( "c = 20 - 16<BR>\n" );
document.write( "c = 4 mph is the current<BR>\n" );
document.write( ":<BR>\n" );
document.write( ";<BR>\n" );
document.write( "Check these solutions in the original equation<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F12 ALIGN=MIDDLE  ALT=\"5%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" >(16-4) = 5<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=5%2F12 ALIGN=MIDDLE  ALT=\"5%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" >*12 = 5<BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" >(16+4) = 5<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F4 ALIGN=MIDDLE  ALT=\"1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > * 20 = 5\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );