Hãy tính a) -11/12 . 4/5 b) -3/13 . -7/8 c) (-2/7)^2 d) (-5) . -10/11

* Hướng dẫn giải

a) $\frac{-11}{12}.\frac{4}{5}=\frac{-11}{15}$

b) $\frac{-3}{13}.\frac{-7}{8}=\frac{21}{104}$

c) ${\left(\frac{-2}{7}\right)}^2=\frac{4}{49}$

d) $\left(-5\right).\frac{-10}{11}=\frac{50}{11}$