Type the correct answer in each box 
functions HNK or inverse functions in both are defined for all real numbers using this relationship what is the value of each function composition
        
                    
             
        
        
        
 This is Commutative property of addition
 
        
                    
             
        
        
        
Yes. 
It’s a flat figure (2D), and all of its lines are connected with one another. There aren’t any open points/lines. It’s closed to create a shape. This means it’s a polygon.
        
             
        
        
        
let h= history books
science books = s
h=2s  there are 2 times as many history as science so to get them equal we double the science
h+s=81    there are 81 total history and science books
2s+s=81   substitute 2s for h in the above equation
3s = 81   combine like terms
s = 27
There are 27 science books
h=2s
h=2(27)
h=54
there are 54 history books