SOLUTION: What’s the answer to this problem A rectangular sandbox is surrounded on all sides by a strip of grass that is 5 feet wide on all sides. The length of the sandbox is 4 feet m

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Question 1182929: What’s the answer to this problem
A rectangular sandbox is surrounded on all sides by a strip of grass that is 5 feet wide on all sides. The length of the sandbox is 4 feet more than the width, and the
total area for the sandbox and the grass is 189 square feet. Find the dimensions of the sandbox.
Answer by ikleyn(52781) About Me  (Show Source):
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A rectangular sandbox is surrounded on all sides by a strip of grass that is 5 feet wide on all sides.
The length of the sandbox is 4 feet more than the width, and the
total area for the sandbox and the grass is 189 square feet. Find the dimensions of the sandbox.
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Let  x  be the width of the large rectangle, in feet; then its length is  (x+4)  feet.


The area equation is


    x*(x+4) = 189.


It gives


    x^2 + 4x - 189 = 0


    x%5B1%2C2%5D = %28-4+%2B-+sqrt%28%28-4%29%5E2%2B4%2A189%29%29%2F2


You need the positive root, ONLY :  x = 11.892 (approximately).


So, the dimensions of the large rectangle are  11.892 ft  and  11.892+4 = 15.892 ft.


The dimensions of the sandbox are 5*2 = 10 ft less than these values.


ANSWER.  The dimensions of the sandbox are  11.892 - 10 = 1.892 ft  and  15.892 - 10 = 5.892 ft.

Solved.