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19 tháng 5

Check lại : 

\(\dfrac{3}{19}.\dfrac{-5}{7}+\dfrac{-18}{19}.\dfrac{3}{14}+\dfrac{6}{19}\)

\(=\dfrac{3}{19}.\dfrac{-5}{7}+\dfrac{3}{19}.\dfrac{-18}{14}+\dfrac{6}{19}\)

\(=\dfrac{3}{19}.\left(\dfrac{-5}{7}+\dfrac{-18}{14}\right)+\dfrac{6}{19}\)

\(=\dfrac{3}{19}.-2+\dfrac{6}{19}\)

\(=\dfrac{-6}{19}+\dfrac{6}{19}\)

\(=0\)

19 tháng 5

\(\dfrac{3}{19}.\dfrac{-5}{7}+\dfrac{-18}{19}.\dfrac{3}{14}+\dfrac{6}{19}\)

\(=\dfrac{3}{19}.\dfrac{-5}{7}+\dfrac{3}{19}.\dfrac{-18}{14}+\dfrac{6}{9}\)

\(=\dfrac{3}{19}.\dfrac{-5}{7}+\dfrac{3}{19}.\dfrac{-9}{7}+\dfrac{2}{3}\)

\(=\dfrac{3}{19}.\left(\dfrac{-5}{7}+\dfrac{-9}{7}\right)+\dfrac{2}{3}\)

\(=\dfrac{3}{19}.-2+\dfrac{2}{3}\)

\(=\dfrac{-6}{19}+\dfrac{2}{3}\)

\(=\dfrac{20}{57}\)

\(=\dfrac{4}{19}\left(\dfrac{-5}{6}-\dfrac{7}{12}-\dfrac{10}{3}\right)\)

\(=\dfrac{4}{19}\cdot\left(\dfrac{-10-7-40}{12}\right)=\dfrac{4}{19}\cdot\dfrac{-57}{12}=-\dfrac{3}{3}=-1\)

2 tháng 4 2023

=\(\dfrac{4}{19}.\left(-\dfrac{5}{6}+-\dfrac{7}{12}\right)-\dfrac{40}{57}\)

=\(-\dfrac{4}{19}-\dfrac{40}{57}\)

=\(-\dfrac{52}{57}\)

27 tháng 1 2022

Bài 1:

\(a,=\frac{2}{3}-\frac{16}{3}=\frac{-14}{3}\)

\(b,=\left(\frac{3}{7}+\frac{4}{7}\right)+\left(-\frac{6}{19}+\frac{-13}{19}\right)=1-1=0\)

\(c,=\frac{3}{5}.\left(\frac{8}{9}-\frac{7}{9}+\frac{26}{9}\right)=\frac{3}{5}.3=\frac{9}{5}\)

8 tháng 2 2022

a,\(\dfrac{1}{2}\).\(\dfrac{4}{3}\)-\(\dfrac{20}{3}\).\(\dfrac{4}{5}\)=\(\dfrac{2}{3}\)-\(\dfrac{16}{3}\)=-\(\dfrac{14}{3}\)

23 tháng 3 2022

\(\dfrac{5}{3}\cdot\dfrac{7}{25}+\dfrac{5}{3}\cdot\dfrac{21}{25}-\dfrac{5}{3}\cdot\dfrac{7}{25}\)

\(=\dfrac{5}{3}\cdot\left(\dfrac{7.}{25}+\dfrac{21}{25}-\dfrac{7}{25}\right)\)

\(=\dfrac{5}{3}\cdot\dfrac{21}{25}=\dfrac{7}{5}\)

b) \(250\%+19\dfrac{3}{11}\cdot\dfrac{7}{26}-6\dfrac{3}{11}\cdot\dfrac{7}{26}\)

\(=\dfrac{5}{2}+\dfrac{212}{11}\cdot\dfrac{7}{26}-\dfrac{69}{11}\cdot\dfrac{7}{26}\)

\(=\dfrac{7}{26}\cdot\left(\dfrac{212}{11}-\dfrac{69}{11}\right)+\dfrac{5}{2}\)

\(=\dfrac{7}{26}\cdot13+\dfrac{5}{2}\)

\(=\dfrac{7}{2}+\dfrac{5}{2}\)

\(=\dfrac{12}{2}=6\)

 

25 tháng 4 2022

\(=\dfrac{5\left(5+2\right)}{11.7}+\dfrac{6}{11}=\dfrac{5}{11}+\dfrac{6}{11}=1\)

25 tháng 4 2022

Ta có:

= 5/11 .( 5/7+ 2/7 ) + 6/11

= 5/11 . 1 + 6/11

= 11/ 11

= 1

#học tốt ạ :3

 

12 tháng 12 2021

\(a,\dfrac{3}{5}+\dfrac{1}{5}.\dfrac{-17}{9}=\dfrac{3}{5}-\dfrac{17}{45}=\dfrac{27}{45}-\dfrac{17}{45}=\dfrac{10}{45}=\dfrac{2}{9}\\ b,\left(-\dfrac{4}{15}-\dfrac{18}{19}\right)-\left(\dfrac{20}{19}+\dfrac{11}{15}\right)=-\dfrac{4}{15}-\dfrac{18}{19}-\dfrac{20}{19}-\dfrac{11}{15}=\left(-\dfrac{4}{15}-\dfrac{11}{15}\right)-\left(\dfrac{18}{19}+\dfrac{20}{19}\right)=-1-2=-3\)

12 tháng 12 2021

\(a,=\dfrac{3}{5}+\left(-\dfrac{17}{45}\right)=\dfrac{2}{9}\)

\(b,=-\dfrac{4}{15}-\dfrac{18}{19}-\dfrac{20}{19}-\dfrac{11}{15}=-3\)

10 tháng 12 2021

a.2/9
b.-3

10 tháng 12 2021

a.2/9 b.(-3)

f: \(=\dfrac{7}{19}\left(\dfrac{8}{11}+\dfrac{3}{11}\right)-\dfrac{12}{19}=\dfrac{7}{19}-\dfrac{12}{19}=\dfrac{-5}{19}\)

i: \(=\left(\dfrac{9}{24}-\dfrac{18}{24}+\dfrac{14}{24}\right)\cdot\dfrac{6}{5}+\dfrac{1}{2}=\dfrac{5}{24}\cdot\dfrac{6}{5}+\dfrac{1}{2}\)

=1/4+1/2=3/4

28 tháng 7 2023

` 7/19 . 8/11 + 3/11 . 7/19 + (-12)/19 `

 

`= 7/19 . ( 8/11 + 3/11 ) + (-12)/19 `

 

`= 7/19 . 11/11 + (-12)/19`

 

`= 7/19 . 1 + (-12)/19 `

 

`= 7/19 + (-12)/19 `

 

`= -5/19 `

 

`( 3/8 + (-3)/4 + 7/12 ) : 5/6 + 1/2`

 

`= 3/8 + (-3)4 + 7/12 . 6/5 + 1/2`

 

`= ( 9+(-18) + 14)/24 . 6/5 + 1/2`

 

`= 5/24 . 6/5 + 1/2`

 

`= 1/4 + 1/2 `

 

`= 3/4`

a: \(=\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(\dfrac{-5}{13}-\dfrac{8}{13}\right)+\left(\dfrac{-18}{35}-\dfrac{17}{35}\right)\)

=1-1-1

=-1

b: \(=\dfrac{-3}{8}\left(\dfrac{1}{6}+\dfrac{5}{6}\right)+\dfrac{-5}{8}=\dfrac{-3}{8}-\dfrac{5}{8}=-1\)

c: \(=\dfrac{4}{4}\cdot\dfrac{5}{15}\cdot\dfrac{11}{11}=\dfrac{1}{3}\)

30 tháng 5 2022

a)\(=\left(-\dfrac{5}{13}+\dfrac{-8}{13}\right)+\left(-\dfrac{18}{35}-\dfrac{17}{35}\right)+\left(\dfrac{3}{14}+\dfrac{14}{17}\right)=-1-1+1=-1\)

 

b)\(=\dfrac{-3}{8}.\left(\dfrac{1}{6}+\dfrac{5}{6}\right)-\dfrac{10}{16}=-\dfrac{3}{8}.1-\dfrac{10}{16}=-\dfrac{6}{16}-\dfrac{10}{16}=-\dfrac{16}{16}=-1\)

c)\(\dfrac{-4.5.11}{11.5.3.-4}=\dfrac{1}{3}\)

8 tháng 5 2022

-5/ 12. (2/11+ 9/11+ (-1)
=-5/ 12. [(11/11+(-1)]

=-5/ 12. (1-1)

= -5/12. 0

=0

8 tháng 5 2022

\(=\dfrac{-5}{12}\times\left(\dfrac{2}{11}+\dfrac{9}{11}-1\right)\)

\(=\dfrac{-5}{12}\times0=0\)