9514 1404 393
Answer:
 $81
Explanation:
The garden is 4 yards = 12 feet by 3 yards = 9 feet. The area of it is the product of these dimensions, ...
 (12 ft)(9 ft) = 108 ft²
The cost of fertilizer for that area will be ...
 ($0.75/ft²)(108 ft²) = $81.00
They will spend $81.00 to fertilize the garden.