Complete question :
The temperature increased 12 degrees between 9 am and noon. it decreased 9 degrees between noon and 6 pm. write an expression with three terms to show the change in temperature. let the first term represent the temperature at 9am.
Answer:
(t + 12 - 9)°F
Explanation:
Let the temperature at 9:00 am = t
Temperature increase between 9:00 am and noon = 12 degrees
Temperature at noon = t + 12
Temperature decreased between noon and 6:00 pm
Temperature at 6:00 pm :
(t + 12) - 9
Hence final temperature at 6:00 pm :
(t + 12 - 9)