Solution
The partial sum of the arithmetic sequence with a = 3, d = 8
[tex]S_n=\frac{n}{2}(2a+(n-1)d)[/tex][tex]\begin{gathered} S_{13}=sum\text{ of the arithmetic sequence where n = 13} \\ S_{13}=\frac{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}[/tex]
Therefore the partial sum of the arithmetic sequence = 663
