Tính giá trị của ​\( N = - \frac{1}{7}\left( {9\frac{1}{2} - 8,75} \right):\frac{2}{7} + 0,625:1\frac{2}{3}\)

* Hướng dẫn giải

 \(\begin{array}{l} N = - \frac{1}{7}\left( {9\frac{1}{2} - 8,75} \right):\frac{2}{7} + 0,625:1\frac{2}{3}\\ N = - \frac{1}{7}\left( {\frac{{19}}{2} - \frac{{875}}{{100}}} \right).\frac{7}{2} + \frac{{625}}{{1000}}:\frac{5}{3}\\ N = - \frac{1}{7}\left( {\frac{{19}}{2} - \frac{{35}}{4}} \right).\frac{7}{2} + \frac{5}{8}.\frac{3}{5}\\ N = - \frac{1}{7}.\frac{3}{4}.\frac{7}{2} + \frac{3}{8}\\ N = - \frac{3}{8} + \frac{3}{8} = 0 \end{array}\)