document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=862757>Question 862757</A>: <I><SPAN STYLE=\"word-break: break-all;\"> David has 280 yards of fencing to enclose a rectangular area. Find the demensions of the rectangle that maximize the enclosed area.What is the maximum area? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #519927 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=519927\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> David has 280 yards of fencing to enclose a rectangular area. Find the demensions of the rectangle that maximize the enclosed area.What is the maximum area?<BR>\n" );
document.write( "***<BR>\n" );
document.write( "let x=width<BR>\n" );
document.write( "let y=length<BR>\n" );
document.write( "2x+2y=280<BR>\n" );
document.write( "x+y=140<BR>\n" );
document.write( "y=140-x)<BR>\n" );
document.write( "..<BR>\n" );
document.write( "Area=xy=x(140-x)=140x-x^2<BR>\n" );
document.write( "=-x^2+140x<BR>\n" );
document.write( "complete the square:<BR>\n" );
document.write( "=-(x^2-140x+4900)+4900<BR>\n" );
document.write( "=-(x-70)^2+4900<BR>\n" );
document.write( "This is an equation of a parabola that  opens down with vertex at (70,4900)<BR>\n" );
document.write( "maximum area=4900 sq yds<BR>\n" );
document.write( "dimensions: 70 by 70 yds, a square. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );