Question

What is the sum of the arithmetic sequence 3, 9, 15…, if there are 34 terms?

Answer 1

\[\S _{n}=n(\frac{a _{1}+a _{n}}{2})\]

Answer 2

What is asubn???

Answer 3

\[a _{n}=a _{1}+(n-1)d\]

Answer 4

\[a _{34}=3+(33)(6)=201\]

Answer 5

\[\S _{n}=34(\frac{3+201}{2})=3468\]