Riley has a farm on a rectangular piece of land that is 200200200 meters wide. This area is divided into two parts: A square area where she grows avocados (whose side is the same as the length of the farm), and the remaining area where she lives. Every week, Riley spends \$3$3dollar sign, 3 per square meter on the area where she lives, and earns \$7$7dollar sign, 7 per square meter from the area where she grows avocados. That way, she manages to save some money every week.