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4. The radius of a cylinder is 3x – 2 cm. The height of the cylinder is x + 3 cm. What is the surface area of the cylinder? Use the formula A = 2r2 + 2rh.

Answer: 2 pie (12x^2 -5x -2) or just D

User TimJohnson
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2 Answers

1 vote
D is your answer. For the entire quick check its.
A-D-B-D-C
100% correct
User Dewalla
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2 votes
Answer:
(24\pi x^2 - 10\pi x - 4\pi) square centimeters

Step-by-step explanation:

Let


image

Then the surface area of the cylinder is given by


A = 2\pi r^2 + 2\pi rh \\ewline \indent = 2\pi r (r+h) \\ewline \indent = 2\pi (3x - 2) (\left ( 3x - 2 \right ) +\left (x + 3 \right )) \\ewline \indent = 2\pi (3x - 2) (4x + 1) \\ewline \indent = 2\pi (12x^2 - 5x - 2) \\ewline \indent \boxed{A = (24\pi x^2 - 10\pi x - 4\pi)cm^2}
User Edison Augusthy
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