To determine how many months Mira's cell phone bill covers, you first need to account for the initial activation fee and then determine how much of the remaining bill can be attributed to the monthly charges.
Here's a breakdown of the operations needed:
- Subtract the activation fee from the total bill to find out how much was spent on monthly charges alone.
- Divide the remaining amount by the monthly charge to find out how many months it covers.
So the correct operations to solve this problem are subtraction and division.
Thus, the response is: subtraction and division.