A rectangular garden is 5 feet longer than twice its width. It has a sidewalk 3 feet wide on two of its sides. The area of the sidewalk is 213 square feet. Find the dimensions of the garden.

2X +5 for length and x for width on the garden. x+ 3 and 2x+ 8 for the sidewalk.

_____________ feet squared.

Follow this example 80 x 120.

The answer is 21 x 47 but i'm not sure what formula was used.

Any help would be appreciated. Thanks