Sharons rectangular vegteable garden is 20 feet by 30 feet. In addition mulching her garden, she wants to put mulch around the outside of her garden in a uniform width. If she has enough mulch to cover an area of 936 sqaure feet, how wide should the mulch border be?

Answer 1

(20+2w)(30+2w) = 936
w = 3

Answer 2

(20+2x)(30+2x) = 936

600 + 100 x + 4 x^2 = 936

4 x^2 + 100 x - 336 = 0

x^2 + 25 x - 84 = 0

(x - 3 )(x + 28) = 0

x = 3 feet