document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=941032>Question 941032</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jack and Danny are bricklayers. Jack can build a certain brick wall in 8 hours whereas Danny takes 11 hours. If they work together, their combined rate decreases by 7 bricks an hour, and it only takes them 5 hours to build the wall together. Find the number of bricks in the wall.\r<BR>\n" );
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document.write( "The rate is constant throughout the time period. As an explicit example, if Jack can lay 10 bricks an hour, and Danny can lay 15 bricks an hour, then their combined rate is 10 + 15 - 7 = 18 bricks an hour. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #573570 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=573570\">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=+b+ ALIGN=MIDDLE  ALT=\"+b+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = the number of bricks in the wall<BR>\n" );
document.write( "Jack's rate:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2F8+ ALIGN=MIDDLE  ALT=\"+b%2F8+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Danny's rate:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2F11+ ALIGN=MIDDLE  ALT=\"+b%2F11+\"   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=+b%2F8+%2B+b%2F11+=+%28+b%2B7+%29%2F5++ ALIGN=MIDDLE  ALT=\"+b%2F8+%2B+b%2F11+=+%28+b%2B7+%29%2F5++\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%285%2F8%29%2Ab+%2B+%285%2F11%29%2Ab+=+b+%2B+7+ ALIGN=MIDDLE  ALT=\"+%285%2F8%29%2Ab+%2B+%285%2F11%29%2Ab+=+b+%2B+7+\"   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=+88+ ALIGN=MIDDLE  ALT=\"+88+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+55b+%2B+40b+=+88b+%2B+616+ ALIGN=MIDDLE  ALT=\"+55b+%2B+40b+=+88b+%2B+616+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+95b+-+88b+=+616+ ALIGN=MIDDLE  ALT=\"+95b+-+88b+=+616+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7b+=+616+ ALIGN=MIDDLE  ALT=\"+7b+=+616+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+88+ ALIGN=MIDDLE  ALT=\"+b+=+88+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "There are <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+88+ ALIGN=MIDDLE  ALT=\"+88+\"   DISABLED_style= \"max-width:90%; height:auto;\" > bricks in the wall<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2F8+%2B+b%2F11+=+%28+b%2B7+%29%2F5++ ALIGN=MIDDLE  ALT=\"+b%2F8+%2B+b%2F11+=+%28+b%2B7+%29%2F5++\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+88%2F8+%2B+88%2F11+=+%28+88%2B7+%29%2F5++ ALIGN=MIDDLE  ALT=\"+88%2F8+%2B+88%2F11+=+%28+88%2B7+%29%2F5++\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+11+%2B+8+=+95%2F5+ ALIGN=MIDDLE  ALT=\"+11+%2B+8+=+95%2F5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+19+=+19+ ALIGN=MIDDLE  ALT=\"+19+=+19+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "I was confused about whether to add or subtract<BR>\n" );
document.write( "the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+ ALIGN=MIDDLE  ALT=\"+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" > in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2F8+%2B+b%2F11+=+%28+b%2B7+%29%2F5++ ALIGN=MIDDLE  ALT=\"+b%2F8+%2B+b%2F11+=+%28+b%2B7+%29%2F5++\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The only way the equation can work is if I add<BR>\n" );
document.write( "the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+ ALIGN=MIDDLE  ALT=\"+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" >. I can force myself to make sense of it<BR>\n" );
document.write( "if I say that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b%2B7+ ALIGN=MIDDLE  ALT=\"+b%2B7+\"   DISABLED_style= \"max-width:90%; height:auto;\" > has to be the \"normal\" rate<BR>\n" );
document.write( "for them working together, and the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+ ALIGN=MIDDLE  ALT=\"+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" > makes<BR>\n" );
document.write( "up for their loss of rate. Hope I got this- definitely<BR>\n" );
document.write( "get another opinion.\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );