SOLUTION: A rectangular pool has dimensions 100m x 200m. Surround the entire pool is a concrete deck (border) of uniform width. The area of the pool is twice the area of the concrete deck.

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Question 1172033: A rectangular pool has dimensions 100m x 200m. Surround the entire pool is a concrete deck (border) of
uniform width. The area of the pool is twice the area of the concrete deck. Using an algebraic solution,
find the width of the concrete deck. Round all answers to 2 decimal places.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
A rectangular pool has dimensions 100m x 200m. Surround the entire pool is a concrete deck (border) of
uniform width. The area of the pool is twice the area of the concrete deck. Using an algebraic solution,
find the width of the concrete deck.
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Area of pool = 100*200 = 20000 sq meters ---- A big pool
w = width
Area of deck + pool = (100+2w)*(200+2w) = 30000
(50+w)*(100+w) = 7500
w^2 + 150w + 5000 = 7500
w^2 + 150w - 2500 = 0
Solve for w, ignore any negative solutions