Question

4.02 Lesson Check Arithmetic Sequences (8)

Answer 1

`a_9= -134`

Explanation:

Us the formula for arithmetic sequence

`a_n = a_1 + d(n -1)`

where

`\rm\:a_n=\:nth\:term\\\:d\:=\:common\:difference\\n\:=\:number\:of\:terms`

Given

`a_1 = -38\\d = - 12\\n = 9`

`a_9 = -38 -12(9 - 1) \\\\a_9 = -38 - 12(8)\\\\a_9= -38 - 96\\\\a_9= -134`