Answer: 
Step-by-step explanation:
For this exercise it is important to remember that:
1. The word "difference" indicates subtraction (The result of a subtraction is called "difference").
2. The multiplication of signs:

For this case, according to the data given in the exercise, the records high temperature and the record low temperature are:

Therefore, if you want to find the difference in the record temperatures, you need to sutract them.
Then you get the following result: