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A cone with height h and radius r has volume V = 13πr2h. If a certain cone with a height of 9 inches has volume V = 3πx2 + 42πx + 147π, what is the cone’s radius r in terms of x?

User Antohoho
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1 Answer

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V = 13πr2h

3πx2 + 42πx + 147π = 13πr2(9)

3πx2 + 42πx + 147π = 117πr2

r2 = (3πx2 + 42πx + 147π) / 117π

r = √((3πx2 + 42πx + 147π) / 117π)
User Bubletan
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