Answer: I think it would be 4a(a−2b squared)
 
        
             
        
        
        
Answer:
d. The variance is 9.56 and the standard deviation is 3.09.
Step-by-step explanation:
From the above question, we are given the following data set.
3, 7, 8, 8, 8, 9, 10, 10, 13, 14
a) Mean = 3 + 7 + 8 + 8 + 8 + 9 + 10 + 10 + 13 + 14/ 10
= 90/10 
= 9
b) Variance
The formula for sample Variance = (Mean - x)²/ n - 1
Mean = 9
n = 10
Sample Variance = 
(3 - 9)² + (7 - 9)² + (8 - 9)² + (8 - 9)² + (8 - 9)² + (9 - 9)² + (10 - 9)² + (10 - 9)² + (13 - 9)² + (14 - 9)² / 10 - 1
= 36 + 4 + 1 + 1 + 1 + 0 + 1 + 1 + 16 + 25/9
= 86/9
= 9.555555556
≈ Approximately 9.56
Variance = 9.56
Sample Standard deviation = √Sample Variance
= √9.56
= 3.0919249667
≈ Approximately 3.09
 
        
             
        
        
        
Answer:
B)
Step-by-step explanation:
 
        
             
        
        
        
Difference of two squares will be 
16y^2 -x^2 = (4y -x)(4y +x)
so the second choice 
        
                    
             
        
        
        
Answer:
(a)  P(x) = 300 x - 3600
(b)  P(340) = $ 98400
(c)  At least 12 items must be sold to avoid losing money.
Step-by-step explanation:
Part (a):
The Profit function is the difference between the revenue function (R(x)) and the Cost (C(x)) function: 
P(x) = R(x) - C(x)
P(x) = 384 x - [84 x + 3600]
P(x) = 384 x - 84 x - 3600
P(x) = 300 x - 3600
Part (b):
The profit on 340 items is: 
P(340) = 300 (340) - 3600
P(340) = 102000 - 3600
P(340) = $ 98400
Part (c):
To avoid losing money, the profit P(x) has to be larger or equal than zero. That is:
P(x)  0
 0
300 x -3600   0
 0
300 x   3600
 3600
x   3600/300
 3600/300
x   12
 12
So at least 12 items must be sold to avoid losing money.