Answer:
The final temperature of the solution was 5°C
Step-by-step explanation:
we know that
1) At the start of an experiment, the temperature of a solution was -12°C
In this moment the temperature is -12°C
2) During the experiment, the temperature of the solution rose 5°C each hour during 4 hours
so
5°C*4=20°C
In this moment the temperature is -12°C+20°C=8°C
3) The temperature changed by -3°C
In this moment the temperature is 8°C-3°C=5°C
