SOLUTION: I am completely confused on how to solve this problem i recieved on a take home test: The sum of the height and radius of a cylinder is 9m. The surface area of the cylinder is 54pi

Algebra ->  Surface-area -> SOLUTION: I am completely confused on how to solve this problem i recieved on a take home test: The sum of the height and radius of a cylinder is 9m. The surface area of the cylinder is 54pi      Log On


   

Question 296421: I am completely confused on how to solve this problem i recieved on a take home test: The sum of the height and radius of a cylinder is 9m. The surface area of the cylinder is 54pie square meters. Write and solve an algebraic equation to find the height and the radius.
Thanks.
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
I am completely confused on how to solve this problem i recieved on a take home test: The sum of the height and radius of a cylinder is 9m. The surface area of the cylinder is 54pie square meters. Write and solve an algebraic equation to find the height and the radius.
Thanks.
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Assuming this includes the top and bottom:
Area+=+2%28pi%2Ar%5E2%29+%2B+2pi%2Ar%2Ah
h = 9 - r
Area+=+2%28pi%2Ar%5E2%29+%2B+2pi%2Ar%2A%289-r%29
54pi+=+2%28pi%2Ar%5E2%29+%2B+2pi%2Ar%2A%289-r%29
27+=+r%5E2%29+%2B+r%2A%289-r%29
27 = 9r
r = 3
h = 6
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PS It's the Greek letter pi, not the dessert, pie