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Glenn cuts half a rectangular lawn, 40m by 30m, by mowing strips of equal width around the perimeter.
\n" ); document.write( " Brad cuts the small rectangular left.
\n" ); document.write( " How wide a strip does Glenn cut so that they share the work equally?
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\n" ); document.write( "Find the area of the whole lawn: 40 * 30 = 1200 sq/m
\n" ); document.write( "then half of lawn: 1200/2 = 60 sq/m
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\n" ); document.write( "Let x = width of the strip mown by Glenn equal half the area
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\n" ); document.write( "Dimension of the remaining rectangle
\n" ); document.write( "(40-2x) by (30-2x)
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\n" ); document.write( "Half the area:
\n" ); document.write( "(40-2x)(30-2x) = 600
\n" ); document.write( "FOIL
\n" ); document.write( "1200 - 80x - 60x + 4x^2 = 600
\n" ); document.write( ":
\n" ); document.write( "1200 - 140x + 4x^2 - 600 = 0
\n" ); document.write( "Arrange as a quadratic equation
\n" ); document.write( "4x^2 - 140x + 600 = 0
\n" ); document.write( "Simplify, divide by 4
\n" ); document.write( "x^2 - 35x + 150 = 0
\n" ); document.write( "Factor
\n" ); document.write( "(x-5)(x-30) = 0
\n" ); document.write( "The reasonable solution is:
\n" ); document.write( "x = 5 m is the width of Glenn's strip
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\n" ); document.write( "Check solution by finding the area of the remaining rectangle
\n" ); document.write( "40-10)*(30-10) = 600
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\n" ); document.write( "Note if they insist on the quadratic formula, solve;
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