Length, Height

[Guest]

A fence is to be constructed.

Length - 10 times the height.

Number of square feet in fence is equal to twice the cube of the height.

Determine length and height of fence.

Let L = Length

Let H = Height

Let S = Square Feet

L = 10H

S = 2x^3H

How do I proceed from here ?

[Guest]

This is how it goes,
L=10H
Area = LH = 2H^3 --> L = 2H^2
Now you replace L,
10H = 2H^2 --> 10 = 2H
H=10/2 = 5 ft
L = 10H = 10x5 = 50 ft
Perimeter (Fence) = 2(H+L) = 2x(5+50) = 110 ft

[Guest]

"L = 2H^2
10 = 2H "

I am not clear on these steps.