Answer:
15
Step-by-step explanation:
 
        
             
        
        
        
This is number 8. the second person got number 9
 
        
        
        
You can look for the number 16 on the x-axis. (bottom line) and put a finger there. Then, look for 19 on the y -axis (left line) and put a finger there. Trace your left finger to the right and your right hand up until they meet. That is (16,19)
        
             
        
        
        
Answer: (-2, 11/6)
Step-by-step explanation: