Answer:
Step-by-step explanation:

Use the formula above to find the surface area of a cylinder.
For the given cylinder the given data is the height (6mi) and diameter (16mi), use the diameter to find the radius:

Surface area:

Then, the surface area of the given cylinder is: 224π square miles
Answer:
8x + 108 = 9
Step-by-step explanation:
Given
x + 9 = 
Multiply through by the lowest common multiple of 3 and 4, that is 12 to clear the fractions.
8x + 108 = 9 ← equivalent equation with no fractions