I suggest you first draw a picture! Call the length of the pool "a" meters and the width "b" meters. The length of the path along the 2 sides is 2a. But the length of the path along the top and bottom is 2b+ 4(x- 8) (because I did not include the four "turning the corners" in the length if the sides). The path's area is 2a(x- 8)+ (2b+ 4(x-8)(x- 8)= 140. The pools perimeter is 2a+ 2b= 46. That is only 2 equations in three unknown values (a, b, and x) but I presume you are being asked to find a and b in terms of x.