### Home > CCA2 > Chapter 10 > Lesson 10.2.1 > Problem 10-89

10-89.

Consider the series 8 + 1 + (−6) + (−13) + … + (−90). Homework Help ✎

How many terms are there?

What is the sum?

Write an expression for the sequence, and find *n* when *t*(*n*) = −90.

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