Equivalent ratio means equal in value
18:4 = 9:2 = 36:8
I believe that the zeros would be -2 and -6, assuming that the first 2 that you wrote in the equation is supposed to be a power to the x.
Answer:

Step-by-step explanation:
the volume of a cylinder is given by:

and the volume of a cone is given by:

since both have the same height and radius, we can solve each equation for
(because this quantity is the same in both figures) and then match the expressions we find:
from the cylinder's volume formula:

and from the cone's volume formula:

matching the two previous expressions:

we solve for the volume of a cone
:

substituting the value of the cylinder's volume 
