Answer:
We have that 
Step-by-step explanation:
We have just to replace n=10 on the general equation

Therefore: 

 
        
             
        
        
        
Answer: it's -1
Step-by-step explanation: Hope this helps 
Can I have brainliest?
 
        
             
        
        
        
Step-by-step explanation:
<h3>Part A</h3>
<u>Angle measures:</u>
- a = x = z = 51° (as vertical angles and corresponding angles)
- b = d = y = w = 180° - 51° = 129° (as supplementary angles and corresponding angles)
<h3>Part B</h3>
Supplementary angles for a linear pair and sum to 180°.
<u>Examples are:</u>
- a and b or 
- a and d or
- x and y etc.
 
        
                    
             
        
        
        
Answer: 
A=3
B=8
C=2
D=5
Step-by-step explanation:
hope this helps