Given the formula for the perimeter of a rectangle:

Where "p" is the perimeter, "l" is the length, and "w" is the width.
You can write a formula for the length of the rectangle by solving the given formula for "l":
1. Apply the Subtraction Property of Equality by subtracting this term from both sides of the equation:

Then:


2. Apply the Division Property of Equality by dividing both sides of the equation by 2:


3. You can rewrite the equation in this form:

Or you can rewrite it in the following form:
- Separate each numerator with the same denominator:

- Simplify:

Hence, the answer is: Option 4.