> your welcome :) and tell me if it’s right
Answer:
Volume: 
Ratio: 
Step-by-step explanation:
First of all, we need to find the volume of the hemispherical tank.
The volume of a sphere is given by:

where
r is the radius of the sphere
V is the volume
Here, we have a hemispherical tank: a hemisphere is exactly a sphere cut in a half, so its volume is half that of the sphere:

Now we want to find the ratio between the volume of the hemisphere and its surface area.
The surface area of a sphere is

For a hemisphere, the area of the curved part of the surface is therefore half of this value, so
. Moreover, we have to add the surface of the base, which is
. So the total surface area of the hemispherical tank is

Therefore, the ratio betwen the volume and the surface area of the hemisphere is

Answer:
y = 8 or y = 0
Step-by-step explanation:
Solve for y over the real numbers:
y^2 - 8 y = 0
Factor y from the left hand side:
y (y - 8) = 0
Split into two equations:
y - 8 = 0 or y = 0
Add 8 to both sides:
Answer: y = 8 or y = 0