Answer:
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) = [tex]4x^{2} = 60x + 225[/tex]
Area of the pool = 15(15) = 225
Now,
The area of the walkway = area of pool and walkway together - area of pool
304 = 4[tex]x^{2}[/tex] + 60x + 225 - 225
304 = [tex]4x^{2}[/tex] + 60x
4[tex]x^{2}[/tex] + 60x - 304 = 0
4([tex]x^{2}[/tex] +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
