document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1037299>Question 1037299</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I would like to fence in a rectangular area in my back yard for my dog. I would like to use chain link fencing, which is only $7 per lineal foot, for both sides and the front. The guy that lives behind me has a dog, and if the two of them see each other, they will be barking all of the time. So, I will need to use solid redwood fencing at $28 per lineal foot to do the back wall.<BR>\n" );
document.write( "I would like the area to be 300 square feet, but do it at a minimum cost. How much of the redwood fencing will I need to buy? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #652011 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=652011\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x=sides<BR>\n" );
document.write( "y=front and back<BR>\n" );
document.write( "xy=300, area<BR>\n" );
document.write( "Cost=7(2x+y)+28y=14x+35y<BR>\n" );
document.write( "y=300/x<BR>\n" );
document.write( "cost is 14x+10500/x<BR>\n" );
document.write( "Take the derivative and set it equal to zero.<BR>\n" );
document.write( "14-10500/x^2=0<BR>\n" );
document.write( "14=(10500/x^2)<BR>\n" );
document.write( "14x^2=10500<BR>\n" );
document.write( "x^2=750<BR>\n" );
document.write( "x=27.38 feet.<BR>\n" );
document.write( "y, the amount of redwood fencing, is 10.96 feet.  Total cost is 65.72@$7=$460.04 plus 10.96*28=306.88=$766.92<BR>\n" );
document.write( "check with 25 and 12 for area of 300<BR>\n" );
document.write( "62 feet of chain ($434)<BR>\n" );
document.write( "12 feet of redwood (336), total is $770.<BR>\n" );
document.write( "30 and 10--90*$7=$630 and 10*$28=$280, for total of $910.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28300%2C200%2C-10%2C40%2C-100%2C2000%2C14x%2B%2810500%2Fx%29%29 ALIGN=MIDDLE  ALT=\"graph%28300%2C200%2C-10%2C40%2C-100%2C2000%2C14x%2B%2810500%2Fx%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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