Answer:
3.33ft
Explanation:
Area of the fence = Length * Width
A = LW
Given
Area A = 30ft²
If the length of the her fence must be one feet greater than three times its width, then;
L = 3W + 1
Substotute into the area formula
A = (3W+1)W
30 = 3W²+W
3W²+W - 30 = 0
(3W²+9W)-(10W - 30) =
3W(W+3)-10(W+3) = 0
3W-10 = 0 and W+3 = 0
3W = 10 and W = -3
W = 10/3 and -3
Width cannot be negative
Hence the maximum width that her fence can be to ensure she doesn't encroach into her neighbor's property is 3.33ft