Answer:
1.  Substitute y = -3x +4 for y in the first equation
2.  Combine like terms and isolate x
3.  Substitute in x into the 2nd equation to get y
Step-by-step explanation:
1.  Substitute y = -3x +4 for y in the first equation
2x- (-3x+4) = 6
2.  Combine like terms
5x -4 = 6
5x -4 +4 = 6+4
5x=10  Divide by 5 to isolate x
5x/5 =10/5
x=2
3. Substitute in x into the 2nd equation to get y
 y = -3x +4 
y = -3(2) +4
y = -6+4
y=-2
(2,-2)
 
        
             
        
        
        
Answer:
Step-by-step explanation:
To find the population variance, we first need the mean:
 so the mean is 7.2. To find the population variance (which is almost exactly the same as the sample variance except for a small difference in the denominators of the formula) we have to take each number minus the mean, and then square the difference. Add together all these squared numbers and then divide by the number of numbers. Like this:
 so the mean is 7.2. To find the population variance (which is almost exactly the same as the sample variance except for a small difference in the denominators of the formula) we have to take each number minus the mean, and then square the difference. Add together all these squared numbers and then divide by the number of numbers. Like this:
 
 
Add together those numbers and divide them by 5:

 
        
             
        
        
        
97.	The great wall is more than 20 000 kilometers long. And about ¾ of it is considered as properly preserved.
I guess you are asking about the value of ¾ which is properly preserved in the said length of the great wall.
=> ¾ = 0.75
Thus, the formula would be like this:
=> 20 000 * .75 = 15 000
Thus, the ¾ value of great wall that is preserved is equals to 15 000 kilometers long,