document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=376475>Question 376475</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It takes Joe 12 hours to paint a fence, but Bob can do the job in 9 hours.  How long does Joe work by himself before being joined by Sam if they finish the job working 3 hours together?\r<BR>\n" );
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document.write( "I've tried setting up a system of equations, but am not having much luck.  I think that the first equation is x/12 + y/9 = 1, with x being the number of hours Joe works and y the number of hours Bob works, but I can't figure out the second equation. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #267841 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=267841\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It takes Joe 12 hours to paint a fence, but Bob can do the job in 9 hours.<BR>\n" );
document.write( " How long does Joe work by himself before being joined by Sam if they finish the job working 3 hours together? <BR>\n" );
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document.write( "We can do it with one equation, but I'm going to ignore Sam's contribution here<BR>\n" );
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document.write( "Let t = time Joe worked by himself<BR>\n" );
document.write( "and<BR>\n" );
document.write( "Bob works 3 hrs<BR>\n" );
document.write( "and<BR>\n" );
document.write( "(t+3) = total time Joe worked<BR>\n" );
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document.write( "Let the completed job = 1<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28t%2B3%29%29%2F12 ALIGN=MIDDLE  ALT=\"%28%28t%2B3%29%29%2F12\"   DISABLED_style= \"max-width:90%; height:auto;\" > + <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F9 ALIGN=MIDDLE  ALT=\"3%2F9\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 1<BR>\n" );
document.write( "Multiply by 36, results:<BR>\n" );
document.write( "3(t+3) + 4(3) = 36<BR>\n" );
document.write( "3t + 9 + 12 = 36<BR>\n" );
document.write( "3t + 21 = 36<BR>\n" );
document.write( "3t = 36 - 21<BR>\n" );
document.write( "3t = 15<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=15%2F3 ALIGN=MIDDLE  ALT=\"15%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = 5 hrs Joe works by himself<BR>\n" );
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document.write( "Let's see if that is true (Joe works 8 hrs total),<BR>\n" );
document.write( "8/12 + 1/3 = 1 </SPAN>\n" );
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