Answer:
13 
Step-by-step explanation:
where n is the number of terms, a1 is the first term and an is the last term. The sum of the first n terms of an arithmetic sequence is called an arithmetic series . Example 1: Find the sum of the first 20 terms of the arithmetic series if a1=5 and a20=62 .An arithmetic sequence is a sequence where the difference between any two consecutive terms is a constant. ... As with any recursive formula, the initial term of the sequence must be given. An explicit formula for an arithmetic sequence with common difference d is given by an=a1+d(n−1) a n = a 1 + d ( n − 1 ) .
 
        
             
        
        
        
Answer:
the first answer is correct Edge 2020
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
503
Step-by-step explanation:
For an arithmetic sequence, the n-th term is found by 

To find  (the common difference) we can simply subtract one of the terms by the last, for example:
 (the common difference) we can simply subtract one of the terms by the last, for example: 

The common difference must be the same throughout the entire sequence, so we can do it once more just to be sure:

We also have to know that  stands for the first term of the sequence, which in this case is 311.
 stands for the first term of the sequence, which in this case is 311. 
Now that we know this, let's find the 32nd term

Good luck!