A 15-ft by 15-ft rectangular swimming pool is surrounded by a walkway of uniform width. If the total area of the walkway is 304 ft^2, how wide is the walkway?

4 ft = width of walkway

Step-by-step explanation:

It helps if you can draw a figure.

Let x = width of walkway

Length of pool + walkway = (2x + 15)

Width of pool + walkway = (2x + 15)

area of pool and walkway together = (2x + 15)(2x + 15) =

Area of the pool = 15(15) = 225

Now,

The area of the walkway = area of pool and walkway together - area of pool

304 = 4 + 60x + 225 - 225

304 = + 60x

4 + 60x - 304 = 0

4( +15x - 76) = 0

4(x - 4)(x + 19) = 0

x = 4    x = -19

-19 must be discarded because a length cannot be negative

Therefore x = 4 ft = width of walkway