\begin{exercice*}
  Compl\'{e}ter.
  \begin{enumerate}
  \item $3 + 4 + 5 + ... + 9 = \sum\limits_{k = ...}^{...}  {...}  $
  \item $1 + \dfrac{1}{2} + \dfrac{1}{4} + \dfrac{1}{8} + \dfrac{1}{{16}}
    = \sum\limits_{k = ...}^{...} {...} $
  \end{enumerate}
\end{exercice*}
\begin{corrige}
  \begin{colenumerate}{2}
  \item $\sum\limits_{k = 3}^9 k $
  \item $\sum\limits_{k = 0}^4 \dfrac{1}{2^k}$
\end{colenumerate}

\vspace{-\baselineskip}
\end{corrige}
