\(60\%x+0,4x+x:3=2\\ \Leftrightarrow\left(60\%+0,4+\dfrac{1}{3}\right)x=2\\ \Rightarrow\dfrac{4}{3}x=2\\ \Rightarrow x=\dfrac{3}{2}\)

\(60\%x+0,4x+x:3=2\) 

\(x.\left(60\%+0,4+\dfrac{1}{3}\right)=2\) 

                          \(x.\dfrac{4}{3}=2\) 

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

                              \(x=\dfrac{3}{2}\)

\(60\%\cdot x+0,4\cdot x+x:3=2\)

\(x\cdot\left(60\%+0,4+\frac{1}{3}\right)=2\)

\(x\cdot\frac{4}{3}=2\)

\(x=2:\frac{4}{3}=\frac{3}{2}\)

 a) \(1\frac{2}{7} = 1 + \frac{2}{7} = \frac{9}{2}\)

\(\begin{array}{l}x:1\frac{2}{7} =  - 3,5\\x:\frac{9}{7} =  - \frac{7}{2}\\x =  - \frac{7}{2}.\frac{9}{7}\\x =  - \frac{9}{2}\end{array}\)

b) \(0,4.x - \frac{1}{5}.x = \frac{3}{4}\)

\(\begin{array}{l}\frac{2}{5}.x - \frac{1}{5}.x = \frac{3}{4}\\\left( {\frac{2}{5} - \frac{1}{5}} \right).x = \frac{3}{4}\\\frac{1}{5}.x = \frac{3}{4}\\x = \frac{3}{4}:\frac{1}{5}\\x = \frac{3}{4}.5\\x = \frac{{15}}{4}\end{array}\)

\(\dfrac{7}{2}\) : \(\dfrac{2}{5}\) = x : \(\dfrac{8}{7}\)

x : \(\dfrac{8}{7}\) = \(\dfrac{7}{2}\) : \(\dfrac{2}{5}\)

x : \(\dfrac{8}{7}\) = \(\dfrac{35}{4}\)

x       = \(\dfrac{35}{4}\) . \(\dfrac{8}{7}\)

x = 10

10

\(a,x\times3=8,4\)

\(x=8,4\div3\)

\(x=2,8\)

\(b,5\times x=0,25\)

\(x=0,25\div5\)

\(x=0,05\)

\(c,0,16\div x=2-0,4\)

\(0,16\div x=1,6\)

\(x=0,16\div1,6\)

\(x=0,1\)

Học tốt

x×3=8,4

x=8,4:3

x=2,8

vậy x=2,8

5×x=0,25

x=0,25:5

x=0,05

0,16:x=2-0,4

0,16:x=1,6

x=0,16:1,6

x=0,1

vậy x=0,1

`Answer:`

Vì đề bài khá khó nhìn nên mình làm thành hai bài nhé. Đề nào đúng thì bạn tham khảo.

`x : (9 1/2 - 3/2 ) = 0,4 + 2/9 - 2/11 . 1/6 + 8/9 - 8/11`

`=> x : ( 19/2 - 3/2 ) = 28/45 - 1/33 + 8/9 - 8/11`

`=> x : 8 = 293/495 + 8/9 - 8/11`

`=> x : 8 = 733/495 - 8/11`

`=> x : 8 = 373/495`

`=> x = 373/495 .8`

`=> x = 2984/495`

`x : ( 9 1/2 - 3/2 ) = (0,4 + 2/9 - 2/11 )/(1,6 + 8/9 - 8/11 )`

`=> x : (19/2 - 3/2 ) = (2 . (1/5 + 1/9 - 1/11))/(8.(1/5 + 1/9 - 1/11))`

`=> x : 8 = 2/8`

`=> x = 2/8 .8`

`=> x = 2`

B)\(\frac{11}{2}+x=\frac{3}{2}-7\)

\(\frac{11}{2}+x=\frac{3}{2}-\frac{14}{2}\)

\(\frac{11}{2}+x=\frac{-11}{2}\)

\(x=\frac{-11}{2}-\frac{11}{2}\)

\(x=\frac{-22}{2}\)

\(x=-11\)

A)\(\frac{1}{3}x+\frac{2}{5}\left(x+1\right)=0\)

\(\frac{1}{3}x+\frac{2}{5}x+\frac{2}{5}=0\)

\(x\cdot\left(\frac{1}{3}+\frac{2}{5}\right)=0-\frac{2}{5}\)

\(x\cdot\left(\frac{5}{15}+\frac{6}{15}\right)=-\frac{2}{5}\)

\(x\cdot\frac{11}{15}=\frac{-2}{5}\)

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

\(x=\frac{-2}{11}\)

nhớ k cho mình nha

a) 1/3 x + 0,4 ( x + 1 ) = 0

<=>  1/3 x + 0,4 . x + 0,4 . 1 = 0

<=> 1/3 x + 0,4 x + 0,4 = 0

<=> x. ( 1/3 + 0,4 ) + 0,4 = 0 

<=> x. 11/15 + 0.4 = 0

<=> x. 11/15 = -2/5

<=> x = -2/5 : 11/15 = - 6/11

b) 1 1/2 + x = 3/2 -7

<=> 3/2 + x = -11/2

<=> x =  -11/2 - 3/2

<=> x = -7  < GOOD LUCK >