Question

Tính bằng cách hợp lí :

\(\left(\dfrac{4}{9}-\dfrac{5}{11}\right):\dfrac{3}{10}+\left(\dfrac{3}{9}-\dfrac{9}{11}\right):\dfrac{3}{10}-\left(\dfrac{2}{9}-\dfrac{8}{11}\right).\left(\dfrac{-10}{3}\right)\)

Các bn giúp mik vs mai mik nộp bài r

Answer 1

\(\left(\dfrac{4}{9}-\dfrac{5}{11}\right):\dfrac{3}{10}+\left(\dfrac{3}{9}-\dfrac{9}{11}\right):\dfrac{3}{10}-\left(\dfrac{2}{9}-\dfrac{8}{11}\right)\cdot\left(-\dfrac{10}{3}\right)\\ =\left(\dfrac{4}{9}-\dfrac{5}{11}\right)\cdot\dfrac{10}{3}+\left(\dfrac{3}{9}-\dfrac{9}{11}\right)\cdot\dfrac{10}{3}-\left(\dfrac{2}{9}-\dfrac{8}{11}\right)\cdot\left(-1\right)\cdot\dfrac{10}{3}\\ =\left(\dfrac{4}{9}-\dfrac{5}{11}\right)\cdot\dfrac{10}{3}+\left(\dfrac{3}{9}-\dfrac{9}{11}\right)\cdot\dfrac{10}{3}+\left(\dfrac{2}{9}-\dfrac{8}{11}\right)\cdot\dfrac{10}{3}=\dfrac{10}{3}\cdot\left(\dfrac{4}{9}-\dfrac{5}{11}+\dfrac{3}{9}-\dfrac{9}{11}+\dfrac{2}{9}-\dfrac{8}{11}\right)\\ =\dfrac{10}{3}\cdot\left(-1\right)\\ =-\dfrac{10}{3}\)

Answer 2

Ta có:(4/9-5/11):3/10+(3/9-9/11):3/10-(2/9-8/11).(-10/3)

=[(4/9-5/11)+(3/9-9/11)]:3/10+(-2/9+8/11).(-10/3)

=[(4/9+3/9)+(-5/11-9/11)]:3/10+(-2/9+8/11):(-3/10)

=(7/9-14/11):3/10+(2/9-8/11):3/10 (nhân chuyển dấu)

=[(7/9-14/11)+(2/9-8/11)]:3/10

=(1-2):3/10

=-1.10/3

=-10/3.