Final answer:
The temperature of the freezer, after leaving the door open, would be -8 degrees Celsius.
Step-by-step explanation:
The temperature of the freezer is -13 degrees Celsius. When Leanna leaves the freezer door open, the temperature of the freezer rises by 5 degrees. To find the temperature of the freezer now, we need to add the change in temperature to the initial temperature. So, -13 degrees + 5 degrees = -8 degrees Celsius.