P is the perimeter of a rectangular garden.
P = 2 L + 2 W,
where L is the length and W is the width of  a rectangle.
W ≤ 30 ft
2 L + 2 W ≤ 180 ft
2 ( L + W ) ≤ 180 Â
L + W ≤ 180 / 2
L + W ≤ 90
Answer:
A system of inequalities:
W ≤ 30
L + W ≤ 90