Add 13 to both sides, which leaves you with k=42. 
 
        
                    
             
        
        
        
There will be 2 books left over if he fills each box.
7 · 4 = 28
30 - 28 = 2
Good Luck
        
             
        
        
        
Answer:

Step-by-step explanation:
I have attached the explanation above. hopefully this will help
 
        
             
        
        
        
Answer:
4.
f(x) = (x + 2)(x + 1)(x - 3) = x^3 - 7·x - 6
a = 0 ; b = -7 ; c = -6
5.
a = -3 ∧ b = -2 ∧ c = -3
 
        
             
        
        
        
TO THE RIGHT izzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz