I usually know how to do these types of problems, but the second variable just threw me off balance. A rancher has 200 feet of fencing to enclose two...

I usually know how to do these types of problems, but the second variable just threw me off balance..47. A rancher has 200 feet of fencing to enclose two adjacent rectangular corrals. What dimensions will produce a maximum enclosed area? (the diagram is of two adjacent corrals sharing a middle fence, y, and each individual corral has length x [so the two together would be 2x for the entire length])I hope I've explained the diagram enough...any help is greatly appreciated!! :D