Answer
=$5\Sigma_{k=1} (-1)^{k} \frac {k}{5}$
Work Step by Step
-Put k=1,2,3,4,5 into $\frac {k}{5}$ and it will be equal
-- 1-$\frac{1}{5}$+$\frac{2}{5}$+$\frac{3}{5}$+$\frac{4}{5}$+$\frac{5}{5}$
--SIgma Notation Will be
=$5\Sigma_{k=1} (-1)^{k} \frac {k}{5}$
