The first one is D because c represents the x and b represents the y. For the second one:
38(2) = 76
180-76 (this is the sum of the unknown measures) 
104/2 (finds the measure of each angle)
52
I am unsure of the final one though. 
Hope this helps!
        
             
        
        
        
For the answer to the question above, 
My answer in which <span>equation represents the boundary for the region where the station can be heard</span> would be multiple choice letter <span>D. (x + 6)^2 + (y + 1)^2 = 16
I hope my answer helped you solve your problem, Have a nice day!</span>
        
             
        
        
        
to solve for y, we must multiply by t on both side to get ride of the t in the denominator. By doing this, we will get:

on the right side.
Subtracting 3, and we have successfully isolated y.
It would be impossible to get a quantitative value for y if we don't know the value of t. 
 
        
                    
             
        
        
        
Answer:
The point (0, 1) represents the y-intercept.
Hence, the y-intercept (0, 1) is on the same line.
Step-by-step explanation:
We know that the slope-intercept form of the line equation
y = mx+b
where 
Given
Using the point-slope form

where 
- m is the slope of the line
In our case:
substituting the values m = 2/3 and the point (-6, -3)  in the point-slope form



Subtract 3 from both sides



comparing with the slope-intercept form y=mx+b
Here the slope = m = 2/3
Y-intercept b = 1
We know that the value of y-intercept can be determined by setting x = 0, and determining the corresponding value of y.
Given the line 

at x = 0, y = 1
Thus, the point (0, 1) represents the y-intercept.
Hence, the y-intercept (0, 1) is on the same line.
 
        
             
        
        
        
Answer/Step-by-step explanation:
Factor this. GCF=2
2(2cos2x+cos x-1)=0
2(2cos x -1)(cos x+1)=0 Set each factor equal to zero and solve
2cos x -1=0 Add 1 to both sides
2cos x =1 Divide by 2
cos x =1/2
x=π/3
x=5π/3
cos x+1=0 Subtract 1 from both sides
cos x=-1
<u><em>x = π</em></u>
<u><em></em></u>