document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=161919>Question 161919</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A circular pool measures 10 feet across. One cubic yard of concrete is to be used to create a circular border of uniform width around the pool. If the border is to have a depth of 4 inches, how wide will the border be?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #119449 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=119449\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A circular pool measures 10 feet across. One cubic yard of concrete is to be used to create a circular border of uniform width around the pool. If the border is to have a depth of 4 inches, how wide will the border be?<BR>\n" );
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document.write( "AN interesting problem<BR>\n" );
document.write( "Let x = width of the concrete border ( in feet)<BR>\n" );
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document.write( "Find the the area of the concrete required rather than the volume<BR>\n" );
document.write( "1 cu yd = 36\" * 36\" * 36\" = 46646 cu/inches<BR>\n" );
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document.write( "Divide this by the 4\" thickness and we have the area<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=46656%2F4 ALIGN=MIDDLE  ALT=\"46656%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 11664 sq/in is area of the concrete<BR>\n" );
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document.write( "Change the area of the concrete to sq/ft<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=11664%2F144 ALIGN=MIDDLE  ALT=\"11664%2F144\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 81 sq/ft is the area of the concrete<BR>\n" );
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document.write( "Find the area of the pool: Ap = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=pi%2A5%5E2 ALIGN=MIDDLE  ALT=\"pi%2A5%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 78.54 sq/ft<BR>\n" );
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document.write( "Total area including the concrete border: 78.54 + 81 = 159.54 sq/ft<BR>\n" );
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document.write( "Radius of the circular area including the border: (x+5)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=pi%2A%28x%2B5%29%5E2 ALIGN=MIDDLE  ALT=\"pi%2A%28x%2B5%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 159.54<BR>\n" );
document.write( "x^2 + 10x + 25 = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=159.54%2Fpi ALIGN=MIDDLE  ALT=\"159.54%2Fpi\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "x^2 + 10x + 25 = 50.78<BR>\n" );
document.write( "x^2 + 10x + 25 - 50.78<BR>\n" );
document.write( "A quadratic equation<BR>\n" );
document.write( "x^2 + 10x - 25.78 = 0<BR>\n" );
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document.write( "Solve this using the quadratic formula<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"x+=+%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( "In our equation: a=1; b=10; c=-25.78<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-10+%2B-+sqrt%2810%5E2+-+4%2A1%2A-25.78+%29%29%2F%282%2A1%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-10+%2B-+sqrt%2810%5E2+-+4%2A1%2A-25.78+%29%29%2F%282%2A1%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-10+%2B-+sqrt%28100+%2B+103.13+%29%29%2F%282%29+ ALIGN=MIDDLE  ALT=\"x+=+%28-10+%2B-+sqrt%28100+%2B+103.13+%29%29%2F%282%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Do the math here and you will find the positive answer:<BR>\n" );
document.write( "x = 2.12 ft is the width of the border<BR>\n" );
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document.write( "Check our solution by finding the vol of concrete<BR>\n" );
document.write( "Overall area - pool area = border area<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=pi%2A%282.12%2B5%29%5E2 ALIGN=MIDDLE  ALT=\"pi%2A%282.12%2B5%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > - 78.54 =<BR>\n" );
document.write( "159.26 - 78.54 = 80.72 sq/ft of concrete<BR>\n" );
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document.write( "Change 80.72 to sq/in: 144 * 80.72 = 11623.68 sq/inches<BR>\n" );
document.write( "Find the vol by multiplying by the thickness 4\"<BR>\n" );
document.write( "11623.68 * 4 = 46494.72 cu/in<BR>\n" );
document.write( "Change to cu yds: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=46495%2F46656 ALIGN=MIDDLE  ALT=\"46495%2F46656\"   DISABLED_style= \"max-width:90%; height:auto;\" > = .997 cu/yds ~ 1 cu/yd </SPAN>\n" );
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