Final answer:
By subtracting 39 from 68, we find out that the second garbage truck collects from 29 trash cans. Adding this amount to the first truck's 68 trash cans, we get a total of 97 trash cans collected by the two trucks.
Step-by-step explanation:
The student's question involves combining two separate quantities of trash cans collected by two garbage trucks and subtracting one amount from the other to find the total. We are told that the first garbage truck collects trash from 68 trash cans and the other collects from 39 fewer trash cans than the first. To solve this, we need to perform two arithmetic operations.
- Firstly, calculate how many trash cans the second truck collects: 68 - 39 = 29 trash cans.
- Then, add the amounts of trash cans collected by both trucks together to find the total: 68 + 29 = 97 trash cans.
Therefore, the two trucks collect trash from 97 trash cans in all.