SOLUTION: A circular fountain in a park includes a concrete wall that is 3 feet high and 2 feet thick. If the inner radius of the wall is x feet, write an algebraic expression in terms of x

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Question 939425: A circular fountain in a park includes a concrete wall that is 3 feet high and 2 feet thick. If the inner radius of the wall is x feet, write an algebraic expression in terms of x that represents the volume of the concrete used to construct the wall. Simplify the expression.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The outer radius is x+2.

Volume is difference of two cylinders.

3%2Api%2A%28x%2B2%29%5E2-3%2Api%2Ax
3pi%28%28x%2B3%29%5E2-x%5E2%29
3pi%28x%5E2%2B6x%2B9-x%5E2%29
3pi%286x%2B9%29
highlight%2818%2Api%2Ax%2B27%29