6 In the cylinder below, the radius, r, is 6 m, and the volume is 252m3. What is the altitude of the cylinder?
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OA. 7 m
OB. 3.5 m
O C. 14 m
OD. 13 m
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So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.