Asquare pool has a side length of x feet. a uniform border around pool is 1 footwide. the total area of the pool and the border os 361 square feet. what is the area of the pool

The total area of pool and border = 361  square feet.

Length of square pool = x

Length of square pool plus border =  (x + 1 +1 ) = x + 2

There is 1 foot length on each side on the x  length.

The other length of the square pool and border =  (x + 2)

Area = (x+2)(x+2)

     (x + 2)(x +2) =  361.            Let A = x +2

        A*A = 361
            A²  = 361    Take square root of both sides
             A  = √361
               A = 19

A = x + 2 = 19
       x = 19 - 2
       x = 17

Area of square pool = x*x = 17*17 = 289

Area of the pool = 289 square feet.