Work shown above! y = 148
 
        
             
        
        
        
The given sequence is
a₁, a₂, ..., 

Because the given sequence is an arithmetic progression (AP), the equation satisfied is

where
d =  the common difference.
The common difference may be determined as
d = a₂ - a₁
The common difference is the difference between successive terms, therefore
d = a₃ - a₂ = a₄ - a₃, and so on..
The sum of the first n terms is

Example:
For the arithmetic sequence
1,3,5, ..., 
the common difference is d= 3 - 1 = 2.
The n-th term is

For example, the 10-term is
a₁₀ = 1 + (10-1)*2 = 19
Th sum of th first 10 terms is
S₁₀ = (10/2)*(1 + 19) = 100
 
        
             
        
        
        
Answer:
x = 1.2375 or 99/90
Step-by-step explanation:
<u>Step 1:  Distribute</u>
21 + 40(2x - 3)
21 + 80x - 120
<u>Step 2:  Combine like terms</u>
21 + 80x - 120
80x - 99
<u>Step 3:  Solve for x</u>
80x - 99 + 99 = 0 + 99
80x / 80 = 99 / 80
x = 1.2375
Answer:  x = 1.2375 or 99/80
 
        
                    
             
        
        
        
28 minutes
45 - 11 divided by 2 = 17 + 11 = 28 minutesa
        
                    
             
        
        
        
Two positives make a positive
two negatives make a positive
1 negative and 1 positive make negative
1 positive and 1 negative make a negative