Answer:
4th is correct answer. 1, 2, 3 not correct you can check the exponents properties
 
        
             
        
        
        
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
 
        
             
        
        
        
The answer for this equation is A
        
             
        
        
        
Um it is the third brainiest please