`1)1/2:2/3 .... 2/3 : 1/2`

`=>1/2xx3/2 .... 2/3xx2`

`=>3/4 .... 4/3`

Vì `3/4 < 1` và `4/3>1` 

`=>3/4<4/3`

__

`4/7:2/5 ... 4/7 : 3/5`

`=>4/7xx5/2....4/7xx5/3`

`=>20/14...20/21`

`=>10/7...20/21`

Vì `10/7>1` và `20/21<1` 

`=>10/7>20/21`

__

`4/15:4/7....2/5xx10/3`

`=>4/15xx7/4...20/15`

`=>7/15...20/15`

Vì `7<20` nên `7/15<20/15`

__

`5/6...15/18-11/18`

`=>5/6...4/18`

Ta có : MSC : `18`

`5/6 = 15/18`

Vì `15>4` nên `5/6 > 4/18`

`2)2/3=(2xx6)/(3xx6)=12/18`

`7/9=(7xx7)/(9xx7)=49/63`

`6/5=(6xx3)/(5xx3)=18/15`

`2/3=(2xx5)/(3xx5)=10/15`

`5/9=(5xx5)/(9xx5)=25/45`

`49/56=(49:7)/(56:7)=7/8`

`6/8=(6xx7)/(8xx7)=42/56`

`2/9=(2xx7)/(9xx7)=14/63`

`49/56=(49:7)/(56:7)=7/8`

a) \(\frac{x}{2}-\frac{11}{5}=\frac{7}{8}.\frac{64}{49}\)

\(\frac{x}{2}-\frac{11}{5}=\frac{8}{7}\)

\(\frac{x}{2}=\frac{8}{7}+\frac{11}{5}\)

\(\frac{x}{2}=\frac{117}{35}\)

\(x=\frac{117}{35}\times2\)

\(x=\frac{234}{35}\)

b) \(\frac{y}{5}+\frac{9}{2}=\frac{6}{7}.\frac{36}{49}\)

\(\frac{y}{5}+\frac{9}{2}=\frac{216}{343}\)

\(\frac{y}{5}=\frac{216}{343}-\frac{9}{2}\)

\(\frac{y}{5}=\frac{-2655}{686}\)

\(y=\frac{-2655}{686}.5\)

\(y=\frac{-13275}{686}\)

ra kết quả to quá bn ạ! Bn xem lại giúp mk nha!

ngắn thui chứ

\(\left(\dfrac{6:\dfrac{3}{5}-\dfrac{17}{16}.\dfrac{6}{7}}{\dfrac{21}{5}.\dfrac{10}{11}+\dfrac{57}{11}}-\dfrac{\left(\dfrac{3}{20}+\dfrac{1}{2}-\dfrac{1}{15}\right).\dfrac{12}{49}}{\dfrac{10}{3}+\dfrac{2}{9}}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\left(\dfrac{\dfrac{509}{56}}{9}-\dfrac{\dfrac{7}{12}.\dfrac{12}{49}}{\dfrac{32}{9}}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\left(\dfrac{509}{504}-\dfrac{\dfrac{1}{7}}{\dfrac{32}{9}}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\left(\dfrac{509}{504}-\dfrac{9}{224}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\dfrac{1955}{2016}.x=\dfrac{215}{96}\)

\(\Rightarrow x=\dfrac{215}{96}:\dfrac{1955}{2016}\)

\(\Rightarrow x=\dfrac{903}{391}\)

`[ 6 : 3/5 - 17/16 . 6/7 : 21/5 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 :  10/3 + 2/9 ] . x = 215/96`

`=>[ 6  . 5/3 - 17/16 . 6/7 . 5/21 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=>[10- 51/56 . 6/7 . 5/21 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> [10- 153/196  . 5/21 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> [10- 255/1372 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> [10- 1275/7546 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> (10- 1275/7546 + 57/11 -  7/12. 12/49 . 3/10 + 2/9 ) . x = 215/96`

`=> ( 10- 1275/7546 + 57/11 -343/600 . 3/10 + 2/9 ) . x = 215/96`

`=> ( 10- 1275/7546 + 57/11 -343/2000 + 2/9 ) . x = 215/96`

`=>15,06357671 . x= 215/96`

`=> x= 215/96: 15,06357671`

`=>x= 0,1486754027`

Đề có phải như vậy không nhỉ ?

a) \(\frac{X}{2}-\frac{11}{5}=\frac{7}{8}\cdot\frac{64}{49}\)

\(\Rightarrow\frac{x}{2}-\frac{11}{5}=\frac{8}{7}\)

\(\Rightarrow\frac{x}{2}=\frac{8}{7}+\frac{11}{5}\)

\(\Rightarrow\frac{x}{2}=\frac{117}{35}\)\(\Rightarrow x=\frac{117}{35}\cdot2=\frac{234}{35}\)

b)\(\frac{x}{5}+\frac{9}{2}=\frac{6}{7}\cdot\frac{36}{49}\)

\(\Rightarrow\frac{x}{5}+\frac{9}{2}=\frac{216}{343}\)

\(\Rightarrow\frac{x}{5}=\frac{216}{343}-\frac{9}{2}=\frac{-2655}{686}\)

\(\Rightarrow x=\frac{-2655}{686}\cdot5=\frac{-13275}{686}\)

        x/2 - 11/5 = 7/8 . 64/49

        x/2 - 11/5 = 8/7

        x/2          =8/7 + 11/5

        x/2          = 117/35

        x             = 2.117/35 ( tính chất phân số bằng nhau)

        x             = 234/35 

       x/5 + 9/2 = 6/7 . 36/49

       x/5 + 9/2 = 216/343

        x/5         = 216/343 - 9/2

        x/5         = -2655/686

        x           = 5.(-2655)/686

        x           = -13275/686 

tui trả lời trước mà ko tk

34

nhớ **** cho mink nka! ^_^

Lời giải chi tiết:

8+1=9

7-5=2

5+2=7

10-6=4

28+1=29

57-5=52

7-35=-28

52+0=52

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