Answer:
-7°C
Step-by-step explanation:
Freezing point of water = 0°C
By adding salt, freezing point lowers by 7°C ;
The freezing point of salt water can be expressed as ;
Since temperature lowers :
Freezing point of salt water :
Freezing point of water - 7°C
0°C - 7°C
= - 7°C