document.write( "Question 1023080: The area of a rectangle with a perimeter of 120 units can be described by y = x (60 - x), where x represents the width of the rectangle and y represents the area. A farmer has 120 yards of fencing available and wishes to enclose a rectangular area. To the nearest five years, what width gives the largest enclosed area?
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Algebra.Com's Answer #638600 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+y+=+x%2A%28+60+-+x+%29+\"$
\n" ); document.write( " $\"+y+=+-x%5E2+%2B+60x+\"$
\n" ); document.write( "This is a parabola with a maximum because
\n" ); document.write( "of the minus sign in front of the $\"+x%5E2+\"$ term
\n" ); document.write( "-------------------
\n" ); document.write( "The formula for x-coordinate of maximum is:
\n" ); document.write( " $\"+x%5Bmax%5D+=+-b%2F%282a%29+\"$
\n" ); document.write( " $\"+a+=+-1+\"$
\n" ); document.write( " $\"+b+=+60+\"$
\n" ); document.write( " $\"+x%5Bmax%5D+=+-60%2F%282%2A%28-1%29%29+\"$
\n" ); document.write( " $\"+x%5Bmax%5D+=+30+\"$
\n" ); document.write( "The width is 30 yds
\n" ); document.write( "-----------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+y+=+x%2A%28+60+-+x+%29+\"$
\n" ); document.write( " $\"+y+=+30%2A%28+60+-+30+%29+\"$
\n" ); document.write( " $\"+y+=+900+\"$ yds2
\n" ); document.write( "-----------------
\n" ); document.write( "Try $\"+x+=+29+\"$ and $\"+x+=+31+\"$
\n" ); document.write( "You should get less than $\"+900+\"$ yds2
\n" ); document.write( "also:
\n" ); document.write( "Let $\"+P+\"$ = perimeter
\n" ); document.write( " $\"+P+=+2x+%2B+2%2A%28+60+-+x+%29+\"$
\n" ); document.write( " $\"+P+=+2%2A30+%2B+2%2A%28+60+-+30+%29+\"$
\n" ); document.write( " $\"+P+=+60+%2B+60+\"$
\n" ); document.write( " $\"+P+=+120+\"$
\n" ); document.write( "OK \n" ); document.write( "

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