document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=90376>Question 90376</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat can go 22km downstream in 2 hours. The return trip takes 6 hours. What would be the speed of the boat if there were no current? 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 #65621 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=65621\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A boat can go 22km downstream in 2 hours. The return trip takes 6 hours. What would be the speed of the boat if there were no current? What is the rate of the current?<BR>\n" );
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document.write( "Let x = speed of the boat in still water<BR>\n" );
document.write( "Let y = speed of the current<BR>\n" );
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document.write( "Speed up-stream = (x-y)<BR>\n" );
document.write( "Speed down-stream = (x+y)<BR>\n" );
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document.write( "Write two distance equations:  Dist = time * speed<BR>\n" );
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document.write( "2(x + y) = 22<BR>\n" );
document.write( "6(x - y) = 22<BR>\n" );
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document.write( "2x + 2y = 22<BR>\n" );
document.write( "6x - 6y = 22<BR>\n" );
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document.write( "Multiply the 1st equation by 3 and add to the 2nd equation:<BR>\n" );
document.write( "6x + 6y = 66<BR>\n" );
document.write( "6x - 6y = 22<BR>\n" );
document.write( "-------------- adding eliminates y<BR>\n" );
document.write( "12x = 88<BR>\n" );
document.write( "x = 88/12<BR>\n" );
document.write( "x = 7<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph boat speed in still water<BR>\n" );
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document.write( "Find y using 6x - 6y = 22<BR>\n" );
document.write( "6(7<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" >)- 6y = 22<BR>\n" );
document.write( "44 - 6y = 22<BR>\n" );
document.write( "-6y = 22 - 44<BR>\n" );
document.write( "y = -22/-6<BR>\n" );
document.write( "y = +3<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2F3 ALIGN=MIDDLE  ALT=\"2%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > mph is the current<BR>\n" );
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document.write( "Check solutions using 2(x + y) = 22<BR>\n" );
document.write( "2(7<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F3 ALIGN=MIDDLE  ALT=\"1%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > + 3<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2%2F3 ALIGN=MIDDLE  ALT=\"2%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" >) = 22<BR>\n" );
document.write( "2(11) = 22<BR>\n" );
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document.write( "Did this make sense to you? Any questions?<BR>\n" );
document.write( "  </SPAN>\n" );
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