Answer:
18 27 36 you just have to do your count byes for 9
 
        
                    
             
        
        
        
Minus
The quadratic equation is
( -b+-SQRT(b^2 - 4ac) )/2a
        
             
        
        
        



which means either 

 or 

. The equation has no solution, since 

 is always bounded between -1 and 1. The second has one solution at 

, and any number of complete revolutions will also satisfy this equation, so in general the solution would be 

 where 

 is any integer.
So you could choose 

 and 

.