Answer: 144 inches.
Step-by-step explanation:
1. To solve this problem you must remember the formula for calculate the perimeter of a rectangle, which is shown below:

Where
is the lenght and
is the width.
2. You know the perimeter and the width, then you can solve for the length, as following:

We have the expression:

When we have rational functions, where the denominator is a function of x, we have a restriction for the domain for any value of x that makes the denominator equal to 0.
That is because if the denominator is 0, then we have a function f(x) that is a division by zero and is undefined.
If we have a value that makes f(x) to be undefined, then this value of x does not belong to the domain of f(x).
Expression:

Answer: There is no restriction for x in the expression.
The group of tiles represent answer A. There are 6 x² tiles, 3 x tiles, and 1 tile.