Đáp án đúng: A
Giải chi tiết:\(\begin{array}{l}a)\,\frac{{31}}{{17}} + \frac{{ - 5}}{{13}} + \frac{{ - 8}}{{13}} - \frac{{14}}{{17}} = \left( {\frac{{31}}{{17}} - \frac{{14}}{{17}}} \right) + \left( {\frac{{ - 5}}{{13}} + \frac{{ - 8}}{{13}}} \right)\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \frac{{17}}{{17}} + \frac{{ - 13}}{{13}}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 1 + \left( { - 1} \right)\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 0\end{array}\)
Chọn A
