document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=808314>Question 808314</A>: <I><SPAN STYLE=\"word-break: break-all;\"> You have an outdoor pool measuring 25 ft x 10 ft.  You want to add a cement walkway around the pool.  If the walkway will be 1 ft thick and you have 304 cubic feet of cement, how wide should the walkway be? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #486931 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=486931\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You have an outdoor pool measuring 25 ft x 10 ft.  You want to add a cement walkway around the pool.  If the walkway will be 1 ft thick and you have 304 cubic feet of cement, how wide should the walkway be?<BR>\n" );
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document.write( "Area of the walkway of width w = (25+2w)*(10+2w) - 25*10<BR>\n" );
document.write( "Area = 250 + 70w + 4w^2 - 250<BR>\n" );
document.write( "= 4w^2 + 70w sq ft<BR>\n" );
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document.write( "Vol = Area*depth<BR>\n" );
document.write( "304 = 4w^2 + 70w<BR>\n" );
document.write( "2w^2 + 35w - 152 = 0<BR>\n" );
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document.write( " <TR><TD  ALIGN=MIDDLE>Solved by <A  rel=nofollow HREF=http://wiki.algebra.com/index.php/Tutoring_-_pluggable_solvers>pluggable</A> solver: <A  rel=nofollow HREF=solve_quadratic_equation.solver>SOLVE quadratic equation (work shown, graph etc)</A></TD></TR>\n" );
document.write( "<TR><TD  ALIGN=LEFT>Quadratic equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ax%5E2%2Bbx%2Bc=0 ALIGN=MIDDLE  ALT=\"ax%5E2%2Bbx%2Bc=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > (in our case <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2x%5E2%2B35x%2B-152+=+0 ALIGN=MIDDLE  ALT=\"2x%5E2%2B35x%2B-152+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" >) has the following solutons:<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  <BR>\n" );
document.write( "  For these solutions to exist, the <U>discriminant</U> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" > should not be a negative number.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  First, we need to compute the discriminant <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" >: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac=%2835%29%5E2-4%2A2%2A-152=2441 ALIGN=MIDDLE  ALT=\"b%5E2-4ac=%2835%29%5E2-4%2A2%2A-152=2441\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  Discriminant d=2441 is greater than zero. That means that there are two solutions: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%5B12%5D+=+%28-35%2B-sqrt%28+2441+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"+x%5B12%5D+=+%28-35%2B-sqrt%28+2441+%29%29%2F2%5Ca\"   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=x%5B1%5D+=+%28-%2835%29%2Bsqrt%28+2441+%29%29%2F2%5C2+=+3.60161932703562 ALIGN=MIDDLE  ALT=\"x%5B1%5D+=+%28-%2835%29%2Bsqrt%28+2441+%29%29%2F2%5C2+=+3.60161932703562\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B2%5D+=+%28-%2835%29-sqrt%28+2441+%29%29%2F2%5C2+=+-21.1016193270356 ALIGN=MIDDLE  ALT=\"x%5B2%5D+=+%28-%2835%29-sqrt%28+2441+%29%29%2F2%5C2+=+-21.1016193270356\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <BR>\n" );
document.write( "    Quadratic expression <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2x%5E2%2B35x%2B-152 ALIGN=MIDDLE  ALT=\"2x%5E2%2B35x%2B-152\"   DISABLED_style= \"max-width:90%; height:auto;\" > can be factored:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2x%5E2%2B35x%2B-152+=+%28x-3.60161932703562%29%2A%28x--21.1016193270356%29 ALIGN=MIDDLE  ALT=\"2x%5E2%2B35x%2B-152+=+%28x-3.60161932703562%29%2A%28x--21.1016193270356%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  Again, the answer is: 3.60161932703562, -21.1016193270356.\n" );
document.write( "Here's your graph:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B35%2Ax%2B-152+%29 ALIGN=MIDDLE  ALT=\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B35%2Ax%2B-152+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ></TD></TR>\n" );
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document.write( "=================<BR>\n" );
document.write( "w =~ 3.6 feet </SPAN>\n" );
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