The associative property of addition is pretty much just any numbers in place of these: a + (b + c) = (a + b) + c. Therefore, your answer would be d) (6 + 1) + 9 = 6 + (1 + 9)
        
             
        
        
        
Answer:
There are 15 men in the dance recital.
Step-by-step explanation:
If 20 people is 4 parts, then 5 people are 1 part. Due to that, 15 people will equal 3 parts.
 
        
             
        
        
        
Answer:
B.  4x + 1
Step-by-step explanation:
4x^2 + 21x + 5 
= (4x + 1)(x + 5)
Factors of this trinomial are (4x + 1) and (x + 5)
Answer
 (4x + 1) 
 
        
             
        
        
        
Answer:
3. D
4. C
5. I don't know sorry
Step-by-step explanation:
 
        
             
        
        
        
4 * 10 = 40
5 * 10 = 50
6 * 10 = 60
The side length of the original large triangle are 40 feet, 50 feet, and 60 feet.