Answer:
The one on the top left
Step-by-step explanation:
What makes a function, a function is that the x coordinate (x,y), cannot be repeated in the tables. The y coordinate can though. 
 
        
             
        
        
        
Answer:
The sum of the exterior angles is 360 degrees.
 
        
             
        
        
        
2(444x+3a+44c) I think so