document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1010003>Question 1010003</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Stephanie  took her kayak to the kaweak river, which flows downstream at a rate of 2 kilometers per hours. She paddled 15 km upstream, and then paddle downstream to her starting point. If this round trip took a total of 4 hours, find the speed that Stephanie can paddle in still water. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #625481 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=625481\">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;\" > = the speed she can paddle in still water in km/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+%2B+2+ ALIGN=MIDDLE  ALT=\"+s+%2B+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the speed of the kayak going downstream in km/hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+-+2+ ALIGN=MIDDLE  ALT=\"+s+-+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the speed of the kayak going upstream in km/hr<BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = her time in hrs to travel 15 km upstream<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4+-+t+ ALIGN=MIDDLE  ALT=\"+4+-+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = her time in hrs to travel 15 km downstream<BR>\n" );
document.write( "----------------------------------------------------<BR>\n" );
document.write( "Her equation for paddling upstream:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+=+%28+s+-+2+%29%2At+ ALIGN=MIDDLE  ALT=\"+15+=+%28+s+-+2+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Her equation for paddling downstream:<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+=+%28+s+%2B+2+%29%2A%28+4+-+t+%29+ ALIGN=MIDDLE  ALT=\"+15+=+%28+s+%2B+2+%29%2A%28+4+-+t+%29+\"   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=+15+=+4s+%2B+8+-+%28+s+%2B+2+%29%2At+ ALIGN=MIDDLE  ALT=\"+15+=+4s+%2B+8+-+%28+s+%2B+2+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+15%2F%28+s+-+2+%29+ ALIGN=MIDDLE  ALT=\"+t+=+15%2F%28+s+-+2+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Substitute (1) into (2)<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+=+4s+%2B+8+-+%28+s+%2B+2+%29%2A%28+15%2F%28+s+-+2+%29+%29+ ALIGN=MIDDLE  ALT=\"+15+=+4s+%2B+8+-+%28+s+%2B+2+%29%2A%28+15%2F%28+s+-+2+%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  <BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+4s+-++%28+s+%2B+2+%29%2A%28+15%2F%28+s+-+2+%29+%29+ ALIGN=MIDDLE  ALT=\"+7+=+4s+-++%28+s+%2B+2+%29%2A%28+15%2F%28+s+-+2+%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >  <BR>\n" );
document.write( "Multiply both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+-+2+ ALIGN=MIDDLE  ALT=\"+s+-+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7%2A%28+s+-+2+%29+=+4s%2A%28+s+-+2+%29+-+15%2A%28+s+%2B+2+%29+ ALIGN=MIDDLE  ALT=\"+7%2A%28+s+-+2+%29+=+4s%2A%28+s+-+2+%29+-+15%2A%28+s+%2B+2+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7s+-+14+=+4s%5E2+-+8s+-+15s+-+30+ ALIGN=MIDDLE  ALT=\"+7s+-+14+=+4s%5E2+-+8s+-+15s+-+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4s%5E2+-+30s+-+16+=+0+ ALIGN=MIDDLE  ALT=\"+4s%5E2+-+30s+-+16+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2s%5E2+-+15s+-+8+=+0+ ALIGN=MIDDLE  ALT=\"+2s%5E2+-+15s+-+8+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Use the quadratic formula<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"+s+=+%28-b+%2B-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+=+2+ ALIGN=MIDDLE  ALT=\"+a+=+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+-15+ ALIGN=MIDDLE  ALT=\"+b+=+-15+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+-8+ ALIGN=MIDDLE  ALT=\"+c+=+-8+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28-%28-15%29+%2B-+sqrt%28+%28-15%29%5E2+-+4%2A2%2A%28-8%29+%29%29+%2F+%282%2A2%29+ ALIGN=MIDDLE  ALT=\"+s+=+%28-%28-15%29+%2B-+sqrt%28+%28-15%29%5E2+-+4%2A2%2A%28-8%29+%29%29+%2F+%282%2A2%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28+15+%2B-+sqrt%28+225+%2B+64+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+s+=+%28+15+%2B-+sqrt%28+225+%2B+64+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28+15+%2B-+sqrt%28+289+%29%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+s+=+%28+15+%2B-+sqrt%28+289+%29%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+%28+15+%2B+17+%29+%2F+4+ ALIGN=MIDDLE  ALT=\"+s+=+%28+15+%2B+17+%29+%2F+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+32%2F4+ ALIGN=MIDDLE  ALT=\"+s+=+32%2F4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+s+=+8+ ALIGN=MIDDLE  ALT=\"+s+=+8+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The speed she can paddle in still water is 8 km/hr<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+=+%28+8+-+2+%29%2At+ ALIGN=MIDDLE  ALT=\"+15+=+%28+8+-+2+%29%2At+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+=+6t+ ALIGN=MIDDLE  ALT=\"+15+=+6t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(1) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+2.5+ ALIGN=MIDDLE  ALT=\"+t+=+2.5+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+=+%28+8+%2B+2+%29%2A%28+4+-+t+%29+ ALIGN=MIDDLE  ALT=\"+15+=+%28+8+%2B+2+%29%2A%28+4+-+t+%29+\"   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+=+10%2A%28+4+-+t+%29+ ALIGN=MIDDLE  ALT=\"+15+=+10%2A%28+4+-+t+%29+\"   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+=+40+-+10t+ ALIGN=MIDDLE  ALT=\"+15+=+40+-+10t+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10t+=+25+ ALIGN=MIDDLE  ALT=\"+10t+=+25+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "(2) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+2.5+ ALIGN=MIDDLE  ALT=\"+t+=+2.5+\"   DISABLED_style= \"max-width:90%; height:auto;\" > hrs<BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );