Answer: 
Step-by-step explanation:
A rectangular prism is a three-dimensional solid.
A rectangular prism has six faces (each one of these faces are rectangles), eight vertices and twelve edges.
You know that this rectangular prism has 5 layers and the volume of one of these layers is 18 cubic centimeters (
).
Assuming that all these layers are equal, the volume of this rectangular prism can be calculated with:

Where
is the volume of one layer.
Substituting, you get:

Answer:
x=13
Step-by-step explanation:
if you will substitute the value of f(x) with 5, you will get the following equation:
5=2x-21
2x=26/÷2
x=13
(I didn't know what you ment when you wrote x2, is it x square or 2X)
I really hope it was the second one, cause that's how I solved it.
It depends on metric or standard.
grams: metric
pounds(lb.): standard
Step-by-step explanation:
circumference =pi × diameter
=(22/7)×2.2
=6.914ft