The temperature after 7 hours is -2° F
<em><u>Explanation</u></em>
At 3 p.m the temperature was 12° F
Then , the temperature began to drop 2° F every hour.
So, the total temperature dropped in 7 hours will be:
° F
Now, for finding the temperature after 7 hours, we need to <u>subtract the "temperature dropped" from the "initial temperature"</u>.
Thus, the temperature after 7 hours
° F