According to the information given in the exercise, Eric had $4.67 and then he earned $3.75.
Then, in order to find the total amount of money he had, you need to use this operation: Addition. This means that you must add $4.67 and $3.75.
Therefore, knowing the above, you can set up the following operation:
Adding the numbers, you get that the sum is (The sum is the result of an addition):
The answer is: He had $8.42