The answer is 2 due to the fact that 2 is even, and can be added more than once.
        
                    
             
        
        
        
Answer:
Yes
Step-by-step explanation:
9 x 3 - (0.6/0.2)   Simplify the parentheses
9 x 3 - 3               Multiply 9 by 3
27 - 3                   Subtract
24
 
        
             
        
        
        
Twenty four millimeters of oil
        
             
        
        
        
Factorise x^2+6x+8=0 to get (x+4)(x+2)=0 
Solve to get x=-4, x=-2
Factorise x^2+6x+13=0 (I assumed you mistyped and wrote * instead of +)
Use the quadratic formula and you find that there are no real roots so the answer for this is just x=-4, x=-2
Tell me if I made any mistakes