Let x be the 1st number
x + 9 be the second number
Equation:
x + x+9 = 171
Solution: 
2x + 9 = 171
2x = 171 - 9
2x = 162
x = 81
x + 9 = 90
81 + 90 = 171
        
             
        
        
        
Answer:
It is not
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
 (x+y)
Step-by-step explanation:

Thus, the HCF is (x+y).
 
        
                    
             
        
        
        
I would love to help you :)
So what do we know?:
We know that side A has a length of 25, and side B has a length of 21. 
So that leaves us to find the length of side C correct? 
Answer
Tbh I'm to lazy to explain how I got this and its mostly likely incorrect. but I think the answer is
 
4
(most likely incorrect LOL)
<u><em>IM SO SORRY IF I MADE YOU FAIL THE QUESTION SDNFKJSDFSDF</em></u>
 
        
                    
             
        
        
        
-6 is the answer since 6*-1 is -6