The area of the striped rectangle in the entire figure is
square units.
To describe the area of the striped rectangle, you can evaluate the expression:

Let's simplify this expression step by step:
Simplify the terms within each set of parentheses:

Multiply the numerators and denominators:

Simplify the fraction:

Reduce the fraction, if possible:

Therefore, the area of the striped rectangle is
square units.