See picture for solution to your problem. 
 
        
             
        
        
        
Well it would be (x+3)(x+3)
using the FOIL method you end up with:
x^2 + 6x + 9
:D
        
             
        
        
        
Answer:
Missing Value Is 4 . 
Step-by-step explanation:
According To The Question, We Have
- A model with 4rows*4squares & 4rows*7squares
         Equation is 16+28 = X*(4+7)
         Solve the above Equation, We get 44=X*11 ⇔ X=4