Answer:
(3x -1) (3x+1)
Step-by-step explanation:
9x^2 - 1
Rewriting
(3x)^2 -1^2
This is the difference of squares a^2 -b^2 = (a+b) (a-b)
(3x -1) (3x+1)
 
        
                    
             
        
        
        
<h2><u><em>Yes, He Has That Correctly</em></u></h2>
        
             
        
        
        
Answer:
Umm I'm not entirely sure but I think its the last one 
 
        
                    
             
        
        
        
It works because even if the numbers are broken apart, you are still multiplying the numbers by their values, it's only different because once broken apart, it's in expanded form instead of standard form. It also makes multiplication easier since you don't have to deal with such large numbers.