Would it be y2 ? idk im not sure but i tried
        
             
        
        
        
Answer:
A. 
 
 
Step-by-step explanation:
Surface area of the original cone 
 
 
When, radius is quadrupled and slant height is reduced to one sixth
 
 
Plug the above values of r and  in equation (1), new surface area becomes:
 in equation (1), new surface area becomes:
 
 
 
 
 

 
        
             
        
        
        
Equivalent ratio means equal in value
18:4 = 9:2 = 36:8
        
             
        
        
        
Answer:
Step-by-step explanation:
 
        
             
        
        
        
That is the vertex form of a quadratic equation