Question

Determine whether the series –5 + 25 – 125 + ... is convergent or divergent.

Answer 1

so lost.... If you can figure it out i will give a medal

Answer 2

\[\begin{align*}-5+25-125+\cdots&=(-5)^1+(-5)^2+(-5)^3+\cdots\\
&=\sum_{n=1}^\infty(-5)^n\end{align*}\]