Điền dấu (< , > , =)thích hợp  vào ô vuông:

- Hướng dẫn giải

a) $\frac{-4}{5}+\frac{-6}{7}=\frac{-28}{35}+\frac{-30}{35}=\frac{-58}{35}<\frac{-35}{35}=-1$

Vậy $\frac{-4}{5}+\frac{-6}{7}<-1$

b) $\frac{1}{6}+\frac{-10}{15}=\frac{1}{6}+\frac{-2}{3}=\frac{1}{6}+\frac{-4}{6}=\frac{-3}{6}=\frac{-1}{2}=\frac{-15}{30}$

$\frac{1}{5}+\frac{-12}{36}=\frac{1}{5}+\frac{-1}{3}=\frac{3}{15}+\frac{-5}{15}=\frac{-2}{15}=\frac{-4}{30}$

 Vậy $\frac{1}{6}+\frac{-10}{15}<\frac{1}{5}+\frac{-12}{36}$