Answer:
Step-by-step explanation:
I think your supposed to add all those numbers together
 
        
                    
             
        
        
        
Answer:
a=d-c/b
Subtract c from both sides 
a=d-c/b 
divide both sides by b
 
        
                    
             
        
        
        
Answer:
1) 91
Step-by-step explanation:
28 + 63 = 91
 
        
             
        
        
        
Answer:
D
Step-by-step explanation:
first of all, what is mode: it is the highest occuring number in a set of numbers.
now since 12 is supposed to be the mean and it occurs twice but 9 also occurs twice so for 12 to be the mode, we must add one more 12.
therefore the answer is 12