document.write( "Question 17784: a farmer has 280 meters of fencing and wants to enclose a rectangular area of 4000 square meters.what dimensions should he use? \n" ); document.write( "
Algebra.Com's Answer #8678 by xcentaur(357)\"\" \"About 
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let the length be x and the width be y
\n" ); document.write( " then 2(x+y)=280 meters [length of fencing]
\n" ); document.write( "and xy=4000 sq m
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\n" ); document.write( "y=4000/x
\n" ); document.write( "substituting in eqn 1 we get,
\n" ); document.write( "2(x+y)=280
\n" ); document.write( "x+y=140
\n" ); document.write( "x+(4000/x)=140
\n" ); document.write( "x^2+4000=140x
\n" ); document.write( "x^2-140x+4000=0
\n" ); document.write( "(x-100)(x-40)=0
\n" ); document.write( "x=100 or 40
\n" ); document.write( "

\n" ); document.write( "then y=4000/x
\n" ); document.write( "thus y=4000/100 or 4000/40
\n" ); document.write( "y=40 or 100
\n" ); document.write( "

\n" ); document.write( "Hence possible dimensions are:
\n" ); document.write( "(length,width) in metres = (100,40) or (40,100)
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\n" ); document.write( "Hope this helps,
\n" ); document.write( "Prabhat \n" ); document.write( "

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