Answer:
The correct answer is x = 6.
Step-by-step explanation:
To solve this problem, we first must recognize that DE + EF = DF.
From this information, we can set up the following equation when we substitute in the given values:
DE + EF = DF
(4x-1) + 9 = 9x - 22
Our first step is going to be to combine like terms on the left side of the equation.  This is modeled below:
4x - 1 + 9 = 9x - 22
4x + 8 = 9x - 22
Then, we should subtract 4x from both sides of the equation.
8 = 5x - 22
Now, we can add 22 to both sides of the equation.
30 = 5x
Finally, we can divide both sides by 5.
x = 6
Therefore, the correct answer is x = 6.
Hope this helps!
 
        
             
        
        
        
Answer:
  
And rounded up we have that n=1068
Step-by-step explanation:
For this case we have the following info given:
 the margin of error desired
 the level of confidence given
The margin of error for the proportion interval is given by this formula:  
    (a)  
the critical value for 95% of confidence is 
We can use as estimator for the population of interest 
. And on this case we have that 
 and we are interested in order to find the value of n, if we solve n from equation (a) we got:  
   (b)  
And replacing into equation (b) the values from part a we got:
  
And rounded up we have that n=1068
 
        
             
        
        
        
Infinite i think. because the two equations are the same.