Answer:
i believe its the third one don't quote me on that though
Step-by-step explanation:
check the picture below.
so, we know the dimensions of the pool, is a 20x10, so its area is simply 200 ft², and we know the walkway is 216 ft², so the whole thing, including pool and walkway is really 200 + 216 ft².
now, as you see in the picture, the dimensions for the combined area is 20+2x and 10+2x, since the walkway is "x" long, therefore,

notice, it cannot be -18, since is a positive length unit.
Answer:
The answer is D.) infinitely many solutions mate
I think the answer is A. 7 5/6