Find $a _ { n } \text { and } a _ { 6 }$ for the following arithmetic sequence.
-$$a _ { 15 } = - 10 , a _ { 17 } = - 44$$
A) $a _ { n } = 228 + 17 ( n - 1 ) , a _ { 6 } = 1180$
B) $a _ { n } = 228 - 17 ( n - 1 ) , a _ { 6 } = 330$
C) $a _ { n } = 228 - 17 ( n - 1 ) , a _ { 6 } = 143$
D) $a _ { n } = 228 - 17 ( n - 1 ) , a _ { 6 } = 126$

Question

Quizplus · Accepted Answer

The common difference $d$ is $-44 - (-10) = -34$ divided by 2, so $d = -17$. Using $a_{15} = -10$, we find the first term $a_1 = 228$. Thus, $a_n = 228 - 17(n-1)$. For $a_6$, substitute $n = 6$ to get $a_6 = 143$.

Find an and a6a _ { n } \text { and } a _ { 6 }an​ and a6​

Find $a _ { n } \text { and } a _ { 6 }$