Đáp án:
≈2,3716
Giải thích các bước giải:
\(
\begin{array}{l}
\frac{1}{{13}} + \frac{3}{{13.23}} + \frac{3}{{23.33}} + ... + \frac{3}{{2303.2306}} \\
= \frac{1}{{13}} + 10(\frac{3}{{13}} - \frac{3}{{23}} + \frac{3}{{23}} - \frac{3}{{33}} + ... + \frac{3}{{2303}} - \frac{3}{{2306}}) \\
= \frac{1}{{13}} + 10(\frac{3}{{13}} - \frac{3}{{2306}}) \\
= \frac{1}{{13}} + 10.\frac{{6879}}{{29978}} \approx 2,3716 \\
\end{array}
\)