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14 tháng 1 2023

\(\dfrac{10}{7}.x=\dfrac{4}{7}\)

\(x=\dfrac{4}{7}:\dfrac{10}{7}\)

\(x=\dfrac{4}{7}.\dfarc{7}{10}\)

\(x=\dfrac{2}{5}\)

5 tháng 5 2022

a/=4/9x10/3=40/27

b/=15/49

c/=4/9x2/3=8/27

5 tháng 5 2022

a)\(=\dfrac{4}{9}\times\dfrac{10}{3}=\dfrac{40}{27}\)

b)\(\dfrac{3}{7}\times\dfrac{5}{7}=\dfrac{15}{49}\)

c)\(\dfrac{4}{9}:\dfrac{3}{2}=\dfrac{4}{9}\times\dfrac{2}{3}=\dfrac{8}{27}\)

9 tháng 4 2022

a: x=4/27-2/3=4/27-18/27=-14/27

b: =>3/4x-1/4x=1/6+7/3

=>1/2x=1/6+14/6=5/2

hay x=5

c: =>13/10x=7/2+5/2=6

=>x=13/10:6=13/60

d: (3x+2)(-2/5x-7)=0

=>3x+2=0 hoặc 2/5x+7=0

=>x=-2/3 hoặc x=-35/2

a) x = 4/27 - 2/3

    x = -14/27

Bài 15:a)\(\dfrac{-2}{5}\)+\(\dfrac{4}{5}\) . x =\(\dfrac{3}{5}\)b)\(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\):x = -2Bài 16a) x - \(\dfrac{10}{3}\) = \(\dfrac{7}{15}\) . \(\dfrac{3}{5}\)b) x + \(\dfrac{3}{22}\)= \(\dfrac{27}{121}\) . \(\dfrac{11}{9}\)c) \(\dfrac{8}{23}\) . \(\dfrac{48}{24}\) - x = \(\dfrac{1}{3}\)d) 1 - x = \(\dfrac{49}{65}\).\(\dfrac{5}{7}\)Bài 17: tìm xa) \(\dfrac{62}{7}\) . x = \(\dfrac{29}{9}\): \(\dfrac{3}{56}\)b) \(\dfrac{1}{5}\) :...
Đọc tiếp

Bài 15:

a)\(\dfrac{-2}{5}\)+\(\dfrac{4}{5}\) . x =\(\dfrac{3}{5}\)

b)\(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\):x = -2

Bài 16

a) x - \(\dfrac{10}{3}\) = \(\dfrac{7}{15}\) . \(\dfrac{3}{5}\)

b) x + \(\dfrac{3}{22}\)\(\dfrac{27}{121}\) . \(\dfrac{11}{9}\)

c) \(\dfrac{8}{23}\) . \(\dfrac{48}{24}\) - x = \(\dfrac{1}{3}\)

d) 1 - x = \(\dfrac{49}{65}\).\(\dfrac{5}{7}\)

Bài 17: tìm x

a) \(\dfrac{62}{7}\) . x = \(\dfrac{29}{9}\)\(\dfrac{3}{56}\)

b) \(\dfrac{1}{5}\) : x=\(\dfrac{1}{5}\)+\(\dfrac{1}{7}\)

bài 18:

a)\(\dfrac{2}{5}\)+\(\dfrac{3}{4}\): x =\(\dfrac{-1}{2}\)

b)\(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)

c) \(\dfrac{1}{2}\)x + \(\dfrac{3}{5}\)x = \(\dfrac{-2}{3}\)

d) \(\dfrac{4}{7}\).x-x = \(\dfrac{-9}{14}\)

bài 19: tính 

\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+\(\dfrac{1}{3.4}\)+...+ \(\dfrac{1}{2018.2019}\)

bài 20:tìm x 

\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+...+\(\dfrac{1}{x.\left(x+1\right)}\)=\(\dfrac{2008}{2009}\)

bài 21: tìm x

\(\dfrac{x+1}{99}\)+\(\dfrac{x+2}{98}\)\(\dfrac{x+3}{97}\)\(\dfrac{x+4}{96}\)=-4

bài 22 : so sánh các phân số sau:

a) \(\dfrac{-1}{5}\)+\(\dfrac{4}{-5}\)và 1

b) \(\dfrac{3}{5}\) và \(\dfrac{2}{3}\)+\(\dfrac{-1}{5}\)

c)\(\dfrac{3}{2}\)+\(\dfrac{-4}{3}\) và \(\dfrac{1}{10}\)+\(\dfrac{-4}{5}\)

d) \(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\) và 2

1
6 tháng 2 2021

help khocroi

6 tháng 2 2021

Hết à bạn

 

11 tháng 6 2021

a, bằng \(\dfrac{10}{7}\) nha em, sorry chị nhìn lộn 5 thành 3

11 tháng 6 2021

a, \(x=\dfrac{-4}{7}:\dfrac{-2}{3}\)

\(\Rightarrow x=\dfrac{6}{7}\)

b, \(\dfrac{2}{3}.x=\dfrac{3}{7}-\dfrac{5}{7}\)

\(\dfrac{2}{3}.x=\dfrac{-2}{7}\)

\(\Rightarrow x=\dfrac{-3}{7}\)

24 tháng 7 2021

a, \(x\) : \(\dfrac{13}{3}\) = -2,5

    \(x\)         = -2,5 . \(\dfrac{13}{3}\)

    \(x\)         = \(\dfrac{65}{6}\)

b,\(\dfrac{3}{5}\)\(x\)         = \(\dfrac{1}{10}-\)\(\dfrac{1}{4}\)

   \(\dfrac{3}{5}x\)         = \(\dfrac{-3}{20}\)

      \(x\)          = \(\dfrac{-3}{20}\) :  \(\dfrac{3}{5}\)

      \(x\)          = \(\dfrac{-1}{4}\)

c, \(\dfrac{25}{9}-\dfrac{12}{13}x=\dfrac{7}{9}\)

              \(\dfrac{12}{13}x\)\(=\dfrac{25}{9}-\dfrac{7}{9}\)

               \(\dfrac{12}{13}x=2\)

                    \(x=2:\dfrac{12}{13}\)

                    \(x=\dfrac{13}{6}\)

 

19 tháng 5 2022

tách đi bạn

19 tháng 5 2022

a) (2x - 3)(6 - 2x) = 0

=> \(\left[{}\begin{matrix}2x-3=0\\6-2x=0\end{matrix}\right.=>\left[{}\begin{matrix}2x=3\\2x=6\end{matrix}\right.=>\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=3\end{matrix}\right.\)

b) \(5\dfrac{4}{7}:x=13=>\dfrac{39}{7}:x=13=>x=\dfrac{39}{7}:13=>x=\dfrac{3}{7}\)

c) \(2x-\dfrac{3}{7}=6\dfrac{2}{7}=>2x-\dfrac{3}{7}=\dfrac{44}{7}=>2x=\dfrac{47}{7}=>x=\dfrac{47}{14}\)

d) \(\dfrac{x}{5}+\dfrac{1}{2}=\dfrac{6}{10}=>\dfrac{x}{5}=\dfrac{6}{10}-\dfrac{1}{2}=>\dfrac{x}{5}=\dfrac{1}{10}=>x.10=5=>x=\dfrac{1}{2}\)

e) \(\dfrac{x+3}{15}=\dfrac{1}{3}=>\left(x+3\right).3=15=>x+3=5=>x=2\)

 

a) \(\dfrac{x}{y}\times\dfrac{3}{4}=\dfrac{5}{6}+\dfrac{1}{3}\)

    \(\dfrac{x}{y}\times\dfrac{3}{4}=\dfrac{7}{6}\)

     \(\dfrac{x}{y}=\dfrac{7}{6}:\dfrac{3}{4}\)

     \(\dfrac{x}{y}=\dfrac{14}{9}\)

 

b) \(\dfrac{7}{9}:\dfrac{x}{y}=\dfrac{10}{7}-\dfrac{13}{14}\)

    \(\dfrac{7}{9}:\dfrac{x}{y}=\dfrac{1}{2}\)

          \(\dfrac{x}{y}=\dfrac{7}{9}:\dfrac{1}{2}\)

            \(\dfrac{x}{y}=\dfrac{14}{9}\)

11 tháng 6 2021

`2/3 x + 5/7 = 3/10`

`2/3 x= 3/10 - 5/7`

`2/3 x=-29/70`

`x = -29/70 : 2/3`

`x=-87/140`

b) `3/4 .x-1/2=3/7`

`3/4 .x=3/7+1/2`

`3/4 .x=13/14`

`x= 13/14 : 3/4`

`x=26/21`

23 tháng 4 2021

viết p/s như nào vậy bạn

23 tháng 4 2021

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9 tháng 5 2022

Bài 1:

+) \(\dfrac{7}{8}\times y=\dfrac{3}{2}+\dfrac{6}{4}=3\)

\(y=3:\dfrac{7}{8}=\dfrac{24}{7}\)

+) \(\dfrac{1}{y}\times\left(\dfrac{2}{5}+\dfrac{1}{5}\right)=\dfrac{10}{3}\)

\(\dfrac{1}{y}=\dfrac{10}{3}:\dfrac{3}{5}=\dfrac{50}{9}\)

\(y=\dfrac{9}{50}\)

9 tháng 5 2022

Bài 2:

+) \(=\dfrac{2}{5}\times\left(\dfrac{4}{7}+\dfrac{3}{7}\right)\)

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

+) \(\dfrac{2}{9}:\dfrac{2}{3}:\dfrac{3}{9}\)

\(\dfrac{2}{9}\times\dfrac{3}{2}\times\dfrac{9}{3}=1\)