Question 838704
A gardener has a 30 foot by 20 foot rectangular plot of ground. She wants to build a 
brick walkway of uniform width on the border of the plot. If the gardener wants to 
have 400 square feet of ground left for planting, how wide (to 2 decimal places) 
should she build the walkway? 
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Draw the picture.
You have a rectangle inside a rectangle.
The outer rectangle is 30 by 20
The inner rectangle is (30-2x) by (20-2x)
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Area of the inner rectangle is 2(15-x)*2(10-x) = 400
(15-x)(10-x) = 100
150-25x + x^2 = 100
x^2 - 25x + 50 = 0
x = 2.1922 ft (width of the walkway)
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Cheers,
Stan H.