-1/8 + -5/3 ; -6/35 . -49/54; -4/5:3/4 tính hộ nhác tính lắm

$\dfrac{-1}{8}+\dfrac{-5}{3}$

$=\dfrac{-3}{24}+\dfrac{-40}{24}$

$=\dfrac{-43}{24}$

.

$\dfrac{-6}{35}.\dfrac{-49}{54}$

$=\dfrac{-6.(-49)}{35.54}$

$=\dfrac{7}{45}$

.

$\dfrac{-4}{5}:\dfrac{3}{4}$

$=\dfrac{-4}{5}.\dfrac{4}{3}$

$=\dfrac{-16}{15}$