Question

please help me! Help me solve this problem. The first three terms of an arithmetic sequence are 9, 16, and 23. Which of the following would be this sequences 20th term?

Answer 1

142

Explanation:

Definition: an = a1 + f × (n-1)

Sequence: 9, 16, 23, 30, 37, 44, 51, 58, 65 ...

Common Difference: +7

The sum of all numbers up through the 20th: 1510

20th value: 142

Hope this helps! :)