Answer:
Given that,
The measure of the rectangular lot is 7x by 7x
The measure of the sports field is 5x by 5x
Area of the lot left over is Area of the rectanglar lot-Area of the sports field
we get,
Area of the rectangle lot
Area of the sports field is,
Area of the lot left over to build bleachers is
Area of the lot left over to build bleachers is 24x^2 square units.