Bt1:Tìm x thuộc Z biết:
a,\(\dfrac{1}{3}\) + \(\dfrac{-2}{5}\) + \(\dfrac{1}{6}\) + \(\dfrac{-1}{5}\) ≤ x < \(\dfrac{-3}{4}\) + \(\dfrac{2}{7}\) + \(\dfrac{-1}{4}\) + \(\dfrac{3}{5}\) + \(\dfrac{5}{7}\)
Bt2:Tìm a,b ϵ N biết: \(\dfrac{a}{5}\) - \(\dfrac{2}{b}\) =\(\dfrac{2}{15}\)