Given: An arithmetic series with:
[tex]\begin{gathered} a_1=22 \\ d=-8 \\ n=12 \end{gathered}[/tex]Required: To find the sum of n terms of the given series.
Explanation: The formula for the sum of n terms of an AP is:
[tex]S_n=\frac{n}{2}[2a_1+(n-1)d][/tex]Substituting the values in the above formula gives:
[tex]S_n=\frac{12}{2}[2\times22+(12-1)\cdot(-8)][/tex]Solving the above equation-
[tex]\begin{gathered} S_n=6(44-88) \\ S_n=-264 \end{gathered}[/tex]Final Answer: The sum of the arithmetic series is -264.
