The general term of a sequence is given. Find the indicated partial sum.
-$$a _ { 1 } = 4 , a _ { n } = a _ { n } - 1 + 6 \text { for } n \geq 2 ; S _ { 5 }$$
A)100
B)80
C)85
D)55

Question

Quizplus · Accepted Answer

The sequence is arithmetic with the first term $a_1 = 4$ and a common difference of 6. The sequence is 4, 10, 16, 22, 28. The partial sum $S_5$ is the sum of the first 5 terms: $4 + 10 + 16 + 22 + 28 = 80$.

The General Term of a Sequence Is Given a1=4,an=an−1+6 for n≥2;S5a _ { 1 } = 4 , a _ { n } = a _ { n } - 1 + 6 \text { for } n \geq 2 ; S _ { 5 }a1​=4,an​=an​−1+6 for n≥2;S5​

The General Term of a Sequence Is Given $a _ { 1 } = 4 , a _ { n } = a _ { n } - 1 + 6 \text { for } n \geq 2 ; S _ { 5 }$