Question 514085
length = x
width = (x-12)

Area = L*W

Area = x(x-12)=540

x^2-12x=540
x^2-12x-540=0
x^2-30x+18x-540=0
x(x-30)+18(x-30)=0
(x-30)(x+18)=0
x=30 which is positive 

length = 30 ft
width = 18 feet

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