Tìm x \(\in\)Z biết
a, \(\frac{1}{3}\)+ \(\frac{-2}{5}\)+ \(\frac{1}{6}\)+ \(\frac{-1}{5}\)\(\le\)x < \(\frac{-3}{4}\)+\(\frac{2}{7}\)+ \(\frac{3}{5}\)+ \(\frac{5}{7}\)+ \(\frac{-1}{4}\)
b, \(\frac{5}{17}\)+ \(\frac{-4}{9}\)+ \(\frac{-20}{31}\)+ \(\frac{12}{17}\)+ \(\frac{-11}{31}\)< x < \(\frac{-3}{7}\)+ \(\frac{7}{15}\)+ \(\frac{4}{-7}\)+ \(\frac{8}{15}\) + \(\frac{2}{3}\)