Final answer:
The electric force between two objects with negative charges is repulsive and decreases as the distance between them increases.
Step-by-step explanation:
The electric force between two charged objects depends on the nature of the charges and the distance between them. In this case, object X has a charge of -4 units and object Y has a charge of -7 units. Since both charges are negative, the force between them is repulsive. Additionally, the force decreases as the distance between the charges increases.