When you convert from meters to centimeters, you always multiply by 100, which means that 1 meter = 1 * 100 cm = 100 cm
So, 8.6 meters = 8.6 * 100 cm = 860 cm 
Hope this Helps :)
        
                    
             
        
        
        
Could you possibly post a more high quality picture so its not blurry thanks!
        
             
        
        
        
This formula solve by discriminant (D=b^2-4ac)
 
        
        
        
Yes. all the friends will get at least one cup of juice