### Home > A2C > Chapter 12 > Lesson 12.1.1 > Problem 12-8

12-8.

If the third term of an arithmetic sequence is 13 and the seventeenth term is −29, what is the eighth term? Homework Help ✎

Create and solve a system of equations based on the sequence *t*(*n*) = *an* + *b*:

13 = 3(−3) + *b*

*b* = 22

42 = −14*a**a* = −3

13 = 3(−3) + *b*

*b* = 22

*t*(8) = (8)(−3) + 22 = −2