a) Ta có:\(\frac{19}{33}\) =\(\frac{38}{66}\); \(\frac{16}{11}\)=\(\frac{96}{66}\); \(\frac{13}{22}\)=\(\frac{39}{66}\)
\(\frac{38}{66}\)<\(\frac{39}{66}\)<\(\frac{96}{66}\)hay \(\frac{19}{33}\)<\(\frac{13}{22}\)<\(\frac{16}{11}\)
Vậy các số hữu tỉ sắp xếp theo thứ tự tăng dần là :\(\frac{19}{33}\);\(\frac{13}{22}\);\(\frac{16}{11}\).
b)Ta có: \(\frac{-18}{12}\)=\(\frac{-630}{420}\); \(\frac{-10}{7}\)=\(\frac{-600}{420}\);\(\frac{-8}{5}\)=\(\frac{-672}{420}\)
\(\frac{-672}{420}\)<\(\frac{-630}{420}\)<\(\frac{-600}{420}\)hay \(\frac{-8}{5}\)<\(\frac{-18}{12}\)<\(\frac{-10}{7}\)
Vậy các số hữu tỉ sắp xếp theo thứ tự tăng dần là: \(\frac{-8}{5}\);\(\frac{-18}{12}\);\(\frac{-10}{7}\).