Answer: 3 boxes of fertilizers in total
Explanation:
Find Area of the grass
Area of the grass = area of the garden - area of the patio
= (lw) - (¹/₂ bh)
= (12 m × 7 m) - (¹/₂ (6m × 3m))
= 84 m² - 9 m²
= 75 m
Determine how many boxes are needed
Since one box contains 32 m²
the number of boxes needed = 75 m² ÷ 32 m²
= 2.34375
(so three boxes in total)