document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=104187>Question 104187</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rectangular plot, bounded on one side by a river, is to be enclosed on the other 3 sides by a fence, and then divided into two equal sized pens by another fence. If you have 900 feet of fence available, what is the largest are that can be enclosed? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #75809 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=75809\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rectangular plot, bounded on one side by a river, is to be enclosed on the other 3 sides by a fence, and then divided into two equal sized pens by another fence. If you have 900 feet of fence available, what is the largest are that can be enclosed?<BR>\n" );
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document.write( "Perimeter would be:<BR>\n" );
document.write( "L + 3W = 900<BR>\n" );
document.write( "or<BR>\n" );
document.write( "L = (900-3W)<BR>\n" );
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document.write( "Area would be:<BR>\n" );
document.write( "A = W * L<BR>\n" );
document.write( "Substitute for L<BR>\n" );
document.write( "A = W(900-3W)<BR>\n" );
document.write( "A = -3W^2 + 900W<BR>\n" );
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document.write( "A quadratic, find the axis of symmetry using: x = -b/(2a); a = -3; b= 900<BR>\n" );
document.write( "W = -900/(2*-3)<BR>\n" );
document.write( "W = -900/-6<BR>\n" );
document.write( "W = 150 ft is the width for max area<BR>\n" );
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document.write( "Find Max area, substitute 150 for W<BR>\n" );
document.write( "A = -3(150^2) + 900(150)<BR>\n" );
document.write( "A = -3(22500) + 135000<BR>\n" );
document.write( "A = -67500 + 135000<BR>\n" );
document.write( "A = +67500 sq ft is max area<BR>\n" );
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document.write( "If you graph it: x = width, y = area <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-50%2C+300%2C+-10000%2C+100000%2C+-3x%5E2%2B900x%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-50%2C+300%2C+-10000%2C+100000%2C+-3x%5E2%2B900x%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "Check it: <BR>\n" );
document.write( "L = 900 - 3(150)<BR>\n" );
document.write( "L = 900 - 450<BR>\n" );
document.write( "L = 450 ft<BR>\n" );
document.write( "So it would be 450 by 150: 450*150 = 67500 sq ft<BR>\n" );
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document.write( "Did this help you? </SPAN>\n" );
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