The temperature after 7 hours is -2° F
Explanation
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: [tex](2*7)=14[/tex]° F
Now, for finding the temperature after 7 hours, we need to subtract the "temperature dropped" from the "initial temperature".
Thus, the temperature after 7 hours [tex]=12-14= -2[/tex]° F
