This problem is an example of an arithmetic series.
The common difference of the second term (15) with the first term (9) and the third term (21) with the second term (15) [15-9=6; 21-15=6] is 6.
The formula for solving this is:
An= A1 +(n-1)*d where An is the nth term, A1 is the first term, n is the number of terms and d is the common difference.
An=9+ (31-1)*6 = 189
The answer is 189.
        
                    
             
        
        
        
You are given
z+9/2 = -3. You are required to get the value of z. Since the equation is an example
of an equality, you can easily get the value of z. The solution of the problem
is,
 
Z + 9/2 = -3
Z = -3 – 9/2
<u>Z = -15/2
or -7.5</u>
<span>There given
choices does not contain the correct answer.</span>
        
                    
             
        
        
        
Answer:
5
Step-by-step explanation:
(+3)+(+2) = 3+2 = 5.
 
        
                    
             
        
        
        
The answer is obviously, A=45, B=57
        
             
        
        
        
Y = 100x + 200
charge for three days of rental; $500
explanation:
y = 100(3) + 200
y = 300 + 200
y = 500