Find the sum,m, $\mathrm { s } _ { \mathbf { n } },$ , o f the sequence.
-$a _ { 1 } = - 8 , d = - 12 ; \text { find } s _ { 6 }$
A)228
B)-120
C)- 228
D)-60

Question

Quizplus · Accepted Answer

The sum of an arithmetic sequence can be found using the formula $s_n = \frac{n}{2}[2a_1 + (n-1)d]$, where $s_n$ is the sum of the first $n$ terms, $a_1$ is the first term, $d$ is the common difference, and $n$ is the number of terms. Here, $a_1 = -8$, $d = -12$, and $n = 6$. Plugging these values into the formula gives $s_6 = \frac{6}{2}[2(-8) + (6-1)(-12)] = 3[-16 - 60] = 3[-76] = -228$.

Find the Sum,m sn,\mathrm { s } _ { \mathbf { n } },sn​,

Find the Sum,m $\mathrm { s } _ { \mathbf { n } },$