The answer is the graph has a relative maximum 
 
        
             
        
        
        
So to get the answer you do 100100100+303030-101010 which = 100302120 x 10 (the amount she/he gets for each subscriber) which is the amount of money Kiersten earned.
Hope this helped 
 
        
             
        
        
        
Answer:
40
Step-by-step explanation:
3u-> 60
1u-> 20
2u->40