To solve this problem, we need to determine the value of x, which represents the cost of topsoil per cubic foot.
We know that the cost of 5 cubic yards of topsoil is $810.
Let's convert cubic yards to cubic feet:
1 cubic yard = 27 cubic feet
5 cubic yards = 5 * 27 = 135 cubic feet
We can set up the equation as follows:
Cost per cubic foot * Number of cubic feet = Total cost
x * 135 = 810
Let's simplify and solve for x:
135x = 810
To isolate x, we divide both sides of the equation by 135:
135x / 135 = 810 / 135
x = 6
The value of x is 6.
The answer is: 6
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Topsoil costs X per cubic foot. What is the cost, in dollars, The cost of 5 cubic yards of topsoil is 810. What is the value of unknown variable X?

### Answer:
