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

 (begin{array}{l} N = – frac{1}{7}left( {9frac{1}{2} – 8,75} right):frac{2}{7} + 0,625:1frac{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})