Elise built a rectangular vegetable garden that is 9 feet long and has an area of 72 square feet.

If you are looking for the width of the garden, it would be 8 feet

If you are asking for the width, then read below for the

Since the area of a rectangle is A = lw, you can fill in the values and then isolate w to find the width.
A = 72
l = 9
72 = 9w
Divide both sides by 9 to isolate w.
72 / 9 = 8
8 = w

If the garden has a length of 9 ft. and area of 72 ft^2, then the width is 8 feet.

Hope this helps!