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A rectangular garden is 30 feet by 40 feet long.
\n" ); document.write( "A walk of uniform width that surrounds it has an area of 280 square feet.
\n" ); document.write( "Find the width of the walk.
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\n" ); document.write( "Find the total area including the garden and walkway
\n" ); document.write( "(30*40) + 280 = 1480 sq/ft
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\n" ); document.write( "Let x = the width of the walkway, the walkway adds 2x to the length and width of the garden
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\n" ); document.write( "Overall area equation
\n" ); document.write( "(2x+40)*(2x+30) = 1480
\n" ); document.write( "FOIL
\n" ); document.write( "4x^2 + 60x + 80x + 1200 = 1480
\n" ); document.write( "4x^2 + 140x + 1200 - 1480 = 0
\n" ); document.write( "4x^2 + 140x - 280 = 0
\n" ); document.write( "Simplify, divide by 4
\n" ); document.write( "x^2 + 35x - 70 = 0
\n" ); document.write( "This won't factor, use the quadratic equation, a=1; b=35; c=-70
\n" ); document.write( "Two solutions but only one makes sense
\n" ); document.write( "x = 1.9 ft is the width of the walkway
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\n" ); document.write( "Confirm our solution by finding the area including the walkway
\n" ); document.write( "(3.8+30)*(3.8+40) = 1480.44 close enough
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