Câu hỏi 51
Tính tổng $2\left[h\left(\frac{1}{2009}\right)+h\left(\frac{2}{2009}\right)+\ldots+h\left(\frac{2008}{2009}\right)\right]$, trong đó
$$
h(t)=\frac{5}{5+25^{t}}, \quad t \in \mathbb{R}
$$
$$
h(t)=\frac{5}{5+25^{t}}, \quad t \in \mathbb{R}
$$