Answer:
178/7
Step-by-step explanation:
4x-7+3x+9=180
4x+3x-7+9=180
7x-7+9=180
7x+2=180
7x=180-2
7x=178
x=178/7
 
        
             
        
        
        
Answer: c) About 16% of the variation in value of the car is explained by a linear relationship with the age of the car.
e) The correlation coefficient, r, is 0.397. 
Step-by-step explanation:
Given that: 
Coefficient of determination (r²) between two variables, age of car (x) and value of car (y) = 0.158
Correlation of determination (r²) of 0.158 = (0.158 × 100% = 15.8% of the variation between the two variables can be explained by the regression line). Hence, about 16% of the variation between age and value of car can be explained by the linear relationship. 
Coefficient of correlation (r) = sqrt(r²) = sqrt(0.158) = 0.397
 
        
             
        
        
        
Answer:
second option
Step-by-step explanation:
Given
 + 6x² + 5 = 0
 + 6x² + 5 = 0
let u = x², then
u² + 6u + 5 = 0 ← in standard form
(u + 1)(u + 5) = 0 ← in factored form
Equate each factor to zero and solve for u
u + 1 = 0 ⇒ u = - 1
u + 5 = 0 ⇒ u = - 5
Change u back into terms of x, that is
x² = - 1 ( take the square root of both sides )
x = ±  = ± i ( noting that
 = ± i ( noting that  = i ), and
 = i ), and
x² = - 5 ( take the square root of both sides )
x = ±  = ±
 = ±  = ±
 = ±  ×
 ×  = ± i
 = ± i
Solutions are x = ± i and x = ± i
 
        
             
        
        
        
Multiply the 3 times 4. Then do the same on the top.
        
             
        
        
        
2
3
-7
24
-25
-3
second row
-12
-2
-9
-38
10
-28