Answer:
Y = [-6  6 6 -6]
Step-by-step explanation:
From the given matrices
If X - 2Y  = Z
b - 2c = a ... 1
a -2d = c ...2
4+2a = 16.... 3
a + 2b = b .... 4
From3 ;
2a = 16-4
2a = 12
a = 6
From 4;
a + 2b - b = 0
a+b = 0
a = -b
6 = -b
b  = -6
From1;
b - 2c = a
-6 - 2c = 6
-2c = 12
c = -6
also
a - 2d = c
6-2d = -6
-2d = -6-6
-2d = -12
d = 6
Hence the matrices Y = [-6  6 6 -6]
 
        
             
        
        
        
Question 20 is 2/11 i believe
        
             
        
        
        
Answer:
Option A
Step-by-step explanation:
Given that A linear model is given for the data in the table: y=1.25x+2.
Let us write observed values for each x and also the predicted values as per equation.
x            2     3        4      8    10      16    20    24    Total
y((O)      3      4        7     12   16      22   28    30
y(P)     4.5   5.75      7     12   14.5   22   27    32
DEv    1.5    1.75      0       0     1.5     0      1       2     7 75
where y(0) represents observed y or y in the table given
y(P) gives values of y predicted as per the equation 1.25x+2
Dev represents the absolute difference
Hence answer is option 
A.7.75
 
        
             
        
        
        
Answer:
24ab-8ac
Step-by-step explanation:
Assuming you want to simplify it.
Original equation: 8a(3b+6c-7c)
Apply 8a to each variable in the paranthesis: (8a)(3b)+(8a)(6c)+(8a)(-7c)
After multiplication: 24ab+48ac-56ac
Combine like terms:  24ab-8ac
 
        
             
        
        
        
51, 51, 51 153 divided by 3 is 51. If you want different ones u could do: 
50, 49, 54