$\frac{2}{3}<\frac{4}{5}$  

 $\frac{2}{3}>\frac{4}{5}$  

 $\frac{2}{3}=\frac{4}{5}$  

 $\frac{3}{9};\ \frac{4}{9};\ \frac{5}{9};\frac{7}{9}$  

 $\frac{3}{9};\ \frac{4}{9};\ \frac{7}{9};\frac{5}{9}$  

 $\frac{7}{9};\ \frac{5}{9};\ \frac{4}{9};\ \frac{3}{9}$  

 $\frac{2019}{2020}\ <\frac{12}{11}$  

 $\frac{2019}{2020}\ >\frac{12}{11}$  

 $\frac{2019}{2020}=\frac{12}{11}$  

 $\frac{11}{15};\ \frac{11}{19};\ \frac{11}{23};\ \frac{11}{25}$  

 $\frac{11}{25};\ \frac{11}{23};\ \frac{11}{19};\ \frac{11}{15}$  

 $\frac{11}{15};\ \frac{11}{23};\ \frac{11}{19};\ \frac{11}{25}$  

 $\frac{15}{7}\ >\frac{19}{14}$  

 $\frac{15}{7}\ <\ \frac{19}{14}$  

 $\frac{15}{7}\ =\ \frac{19}{14}$  

Tổ một

Tổ hai

Tổ ba