Answer:
a. 16
b. 26
c. (11,13) and (17,19)
d. 3,8,12
Step-by-step explanation:
1. 2x8 = 16, sum of 1 +6 ( 2 digits)= 7
2. 2+3+5+7+11= 28
3. 10 to 20 ( 11,13,17,19) so we can make a pair that has difference of 2 like (11,13)
4. I will attach
 
        
             
        
        
        
Answer:
variability and stay the same
Step-by-step explanation:
 
        
             
        
        
        
Answer:
x = 17
Step-by-step explanation:
-1 is the same as minus-ing it by 1.
10 + x - 1 = 26.
10 + 16 - 1 = 25, so it must not be x = 16.
x = 17. lets try it.
10 + 17 - 1 = 26!!
 
        
                    
             
        
        
        
Answer: 
1. b
2. a
3. d
4. c
Step-by-step explanation: