At 5 a. M. , the temperature at an airport was −9. 4°F. Six hours later, the temperature was 2. 8°F. Which expression represents the total temperature change over the six hours?
∣∣−9. 4+2. 8∣∣
−9. 4+2. 8
∣∣2. 8−(−9. 4)∣∣
∣∣2. 8+(−9. 4)∣∣