Question

Tính nhanh:

Answer 1

\(=\dfrac{3}{7}\left(-\dfrac{5}{9}-\dfrac{4}{9}\right)-\dfrac{4}{7}=\dfrac{-3}{7}-\dfrac{4}{7}=-1\)

Answer 2

\(\dfrac{3}{7}.\dfrac{-5}{9}+\dfrac{3}{7}.\dfrac{-4}{9}-\dfrac{4}{7}\\ =\dfrac{3}{7}\left(\dfrac{-5}{9}+\dfrac{-4}{9}\right)-\dfrac{4}{7}\\ =\dfrac{3}{7}.\dfrac{-9}{9}-\dfrac{4}{7}\\ =\dfrac{3}{7}.\left(-1\right)-\dfrac{4}{7}\\ =\dfrac{-3}{7}-\dfrac{4}{7}\\ =\dfrac{-7}{7}\\ =-1\)

Answer 3

bằng -1 bạn nhé