Please help me and you will get 10 points

Joe wants to build a swimming pool surrounded by a side walk of uniform width. He wants the dimensions of the pool and sidewalk to be 16 meters by 20 meters. The poll has an area of 192 square meters. How wide should the sidewalks be? Make a quadratic equation and solve it by using factoring. Please help me and you will get 10 points.

Length of Pool and Sidewalk = 20 ft.
Width of Pool and Sidewalk = 16 ft.
Width of Sidewalk = w
Length of Pool = 20 - 2w
Width of Pool = 16 - 2w
Area of Pool, A = 192 sq. ft.

(20 - 2w)(16 - 2w) = A
320 - 40w - 32w + 4w² = 192
320 - 72w + 4w² = 192
4w² - 72w + 320 - 192 = 0
4w² - 72w + 128) = 0
w² - 18w + 32 = 0
(w - 2)(w - 16) = 0

w {2, 16}

Since a width of 16 ft. would be the same as the width of the pool,

w = 2

The sidewalk should be 2 ft. wide.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

See Diagram: http://i533.photobucket.com/albums/ee339…
...

(16 -- 2w)(20 -- 2w) = 192
OR w^2 -- 18w + 32 = 0
OR (w -- 2)(w -- 16) = 0
whence w = 2, w = 16 is not possible
side walk is 2 m wide.