Question

I have a partial sum question for a geometric sequence picture included

Answer 1

The partial sum of the arithmetic sequence with a = 3, d = 8

`S_n=(n)/(2)(2a+(n-1)d)`
`\begin{gathered} S_(13)=sum\text{ of the arithmetic sequence where n = 13} \\ S_(13)=(13)/(2)(2(3)+(13-1)8) \\ S_(13)=6.5(6+12(8)) \\ S_(13)=6.5(6+96) \\ S_(13)=6.5(102) \\ S_(13)=663 \end{gathered}`

Therefore the partial sum of the arithmetic sequence = 663