SOLUTION: I am in need of help A rectangle garden is to be surrounded by a walkway of constant width. The gardens dimensions are 30ft by 40ft. The total area, garden plus walkway is 1800f

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Question 93534: I am in need of help
A rectangle garden is to be surrounded by a walkway of constant width. The gardens dimensions are 30ft by 40ft. The total area, garden plus walkway is 1800ft^2. What must be the width of the walkway to the nearest thousandth?
Thank you
Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website!
This same problem came up a couple weeks ago. This is what I submitted then, perhaps it will help you.
:
A rectangular garden is to be surrounded by a walkway of constant width. The garden's dimensions are 30ft by 40ft. The total area, garden plus walkway, is to be 1800ft^2. What must be the width of the walkway to the nearest thousandth?
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Let x = width of the walkway
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Draw this out labeling the walkway width as x, and the inner rectangle
representing the garden as 30 by 40. It will be apparent that the overall
dimensions will be (2x+30) by (2x+40), the area of that is given as 1800 sqft
:
(2x + 30) * (2x + 40) = 1800
:
FOIL
4x^2 + 140x + 1200 = 1800
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4x^2 + 140x + 1200 - 1800 = 0
:
4x^2 + 140x - 600 = 0
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Simplify, divide eq by 4 and you have:
x^2 + 35x - 150 = 0
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Use the quadratic formula to find x: a=1; b=35; c=-150

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:

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Do the math and you will get two solutions; -38.86 and +3.86,
obviously it's x = 3.86
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3.86 ft is the width of the walkway
:
:
Check it:
2x = 2(3.86) = 7.72
So we have:
37.72 * 47.72 = 1799.998 ~ 1800 sq ft
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How about this? Did it make sense to you? Any questions?