Based on the starting temperature and the new temperature, the relevant expression would be 2 - (-9)
To find the number of degrees the temperature has changed by, use the following equation:
= Starting temperature - Current temperature
Starting temperature = 2°F
Current temperature = -9°F
The equation becomes:
= 2 - (-9)
In conclusion, the expression would be 2 - (-9)
Find out more on expressions at https://brainly.com/question/945593.
