-\(\frac{-1}{7}< x< \frac{-1}{8}\) => \(\frac{-1\cdot56}{7\cdot56}< x< \frac{-1\cdot49}{8\cdot49}\)=> \(\frac{-56}{392}< x< \frac{-49}{392}\)
=> 6 số đó là: \(\frac{-55}{392};\frac{-54}{392};\frac{-53}{392};\frac{-52}{392};\frac{-51}{392};\frac{-50}{392}\)