Awalkway of uniform width is to be built around a square swimming pool with 18-foot edges. how wide should the walkway be to make the area of the walkway’s surface 400 feet? a. 5.25 ft c. 4.45 ft b. 4.25 ft d. 6.35 ft

an 18 ft square with a uniform border of width x

the area of the border is 400 ft²

x

The outside dimension of the square with the border added is 18+2x, so the total area of square and border is (18+2x)². Subtracting the area of the original square gives the area of the border.

... (18+2x)² -18² = 400

... 4x² +72x = 400 . . . . . simplify

... x² + 18x = 100 . . . . . . .divid by 4

... x² +18x +9² = 100 +9² . . . . complete the square

... (x +9)² = 181 . . . . . . . . .simplify

... x = √181 -9 . . . . . . . . . take the square root, subtract 9

... x ≈ 4.4536 . . . . . . . . . evaluate

The appropriate choice is ...

... c. 4.45 ft

C on edge:)

Step-by-step explanation:

step-by-step explanation:

bob the banana