Answer:
2 tomato plants will left with Clara.
Step-by-step explanation:
Length of the garden = l = 7 feet
Width of the garden = w = 4 feet
Area of the garden = l × w

Area occupied by single tomato plant = 
Number of tomato plants in the garden :
tomato plants
Number of tomato Clara has is 30
Number plants leftover with Clara = 30 - 28 = 2
2 tomato plants will left with Clara.