document.write( "Question 1118629: A farmer has 800 metres of wire with which to fence 3 rectangular paddocks side by side. The width of the paddocks is x metres and the sum of their lengths is y metres.
\n" ); document.write( "a)show that the total area of the paddocks is given by A= 400x-2x^2
\n" ); document.write( "b) find the greatest area that can be enclosed \n" ); document.write( "
Algebra.Com's Answer #734011 by ankor@dixie-net.com(22740)\"\" \"About 
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A farmer has 800 metres of wire with which to fence 3 rectangular paddocks side by side.
\n" ); document.write( " The width of the paddocks is x metres and the sum of their lengths is y metres.
\n" ); document.write( "a)show that the total area of the paddocks is given by A= 400x-2x^2
\n" ); document.write( "4x + y = 800
\n" ); document.write( "y = -4x + 800
\n" ); document.write( "therefore
\n" ); document.write( "\"1%2F2\"(-4x+800) = -2x+400 = the length (L)
\n" ); document.write( ":
\n" ); document.write( "A = width * length
\n" ); document.write( "A = x*(-2x+400)
\n" ); document.write( "A = -2x^2 + 400x
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "b) find the greatest area that can be enclosed
\n" ); document.write( "The above is a quadratic equation, max area is on the axis of symmetry
\n" ); document.write( "x = b/(2a), where a=-2, b = 400
\n" ); document.write( "x = \"%28-400%29%2F%282%2A-2%29\"
\n" ); document.write( "x = +100 m is the width for max area
\n" ); document.write( "Find the length
\n" ); document.write( "L = -2x + 400
\n" ); document.write( "L = -2(100) + 400
\n" ); document.write( "L = 200 is the length
\n" ); document.write( "Max area: 100 * 200 = 20,000 sq meters
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