Answer:
D) x = 4, y = -2, z = 3
Step-by-step explanation:
x = 3z − 5
2x + 2z = y + 16 
2(3z - 5) + 2z = y + 16
6z - 10 + 2z = y + 16
8z = y + 26 ---> (A)
7x − 5z = 3y + 19
7(3z - 5) - 5z = 3y + 19
21z - 35 - 5z = 3y + 19
16z = 3y + 54 ---> (B)
8z = y + 26
16z = 3y + 54 
2(y + 26) = 3y + 54
2y + 52 = 3y + 54
y = -2
8z = -2 + 26
8z = 24
z = 3
x = 3(3) - 5
x = 4
 
        
             
        
        
        
The mean will be 5 points higher...so...c would be the answer!
        
                    
             
        
        
        
Sum sum sum sum sum sums calculator use google to find sum times 9$
        
             
        
        
        
Answer:
3x+6.9 and 3x-4
Step-by-step explanation:
since 3 x x is 3x and the sign in the bracket is addition you place it there then place 3 x 2.3 
being 6.9.
1/3 x 9is 9/3 and 3 can multiply both sides to get 3/1 or 3 then bring the minus and 1/3 x 12 is 12/3 3 can multiply both sides to get 4/1 or 4