Answer:
The temperature is of -4º at midnight.
The temperature has to rise by more than 4º after midnight to be above freezing.
Explanation:
The day starts out at 2° and warms up 9° more by noon.
So temperature of 2 + 9 = 11º at noon.
It warms another 2° before dropping quickly 17° by midnight.
The temperature after midnight is of:
11º + 2º - 17º = 13º - 17º = -4º.
The temperature is of -4º at midnight.
How many degrees would the temperature need to rise after midnight to be above freezing?
Add x, has to be higher than 0. So
-4º + x > 0º
x > 4º
The temperature has to rise by more than 4º after midnight to be above freezing