Answer:
Required equation :

Weight of each of his checked bags = 15.5 kg
Explanation:
Number of checked bags = 2
Backpack weight = 4 kg
The total weight of Carl's baggage = 35kg
Let w is the weight of each checked bag.
Weight of 2 checked bags = 2w
Weight of 2 checked bags + Backpack weight = Total weight of Carl's baggage

Subtract 4 from both sides.

Divide 2 from both sides.

Therefore, the weight of each of his checked bags is 15.5 kg.