x - 2/3 = 3/5 - 1/4

x - 2/3 = 7/20

x = 7/20 + 2/3 

x = 61/60

- 2/3 . x + 1/5 = 1/10

-2/3 . x = 1/10 - 1/5

- 2/3 . x = -1/10

x = -1/10 : -2/3

x = 3/20

\(a,x-1\dfrac{3}{5}=2\dfrac{1}{10}\\ x-\dfrac{8}{5}=\dfrac{21}{10}\\ x=\dfrac{21}{10}+\dfrac{8}{5}\\ x=\dfrac{21}{10}+\dfrac{16}{10}\\ x=\dfrac{37}{10}\\ b,5\dfrac{1}{7}:x=4\dfrac{1}{2}\\ \dfrac{36}{7}:x=\dfrac{9}{2}\\ x=\dfrac{36}{7}:\dfrac{9}{2}\\ x=\dfrac{36}{7}\cdot\dfrac{2}{9}\\ x=\dfrac{8}{7}\)

\(a,\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}+\dfrac{5}{7}=9\dfrac{5}{7}\)

\(\Leftrightarrow\left(x-\dfrac{1}{2}\right).3=\dfrac{68}{7}-\dfrac{5}{7}\)

\(\Leftrightarrow\left(x-\dfrac{1}{2}\right).3=9\)

\(\Leftrightarrow x-\dfrac{1}{3}=3\)

\(\Leftrightarrow x=3+\dfrac{1}{3}\)

\(\Leftrightarrow x=\dfrac{9}{3}+\dfrac{1}{3}\)

\(\Leftrightarrow x=\dfrac{10}{3}\)

\(b,x+30\%x=-1,31\)

\(\Leftrightarrow x+\dfrac{3}{10}.x=-\dfrac{131}{100}\)

\(\Leftrightarrow x.\left(1+\dfrac{3}{10}\right)=-\dfrac{131}{100}\)

\(\Leftrightarrow x.\dfrac{13}{10}=-\dfrac{131}{100}\)

\(\Leftrightarrow x=-\dfrac{131}{100}.\dfrac{10}{13}\)

\(\Leftrightarrow x=-\dfrac{131}{130}\)

\(c,-\dfrac{2}{3}x+\dfrac{1}{5}=\dfrac{1}{10}\)

\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{1}{10}-\dfrac{1}{5}\)

\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{1}{10}-\dfrac{2}{10}\)

\(\Leftrightarrow-\dfrac{2}{3}x=-\dfrac{1}{10}\)

\(\Leftrightarrow x=-\dfrac{1}{10}.\left(-\dfrac{3}{2}\right)\)

\(\Leftrightarrow x=\dfrac{3}{20}\)

a.\(\dfrac{1}{3}\) + x  = \(\dfrac{5}{6}\)

       x = \(\dfrac{5}{6}\) - \(\dfrac{1}{3}\)

      x = \(\dfrac{1}{2}\)

b. | x-1| - \(\dfrac{2}{5}\) = \(\dfrac{11}{10}\) 

   | x-1|        = \(\dfrac{11}{10}\) + \(\dfrac{2}{5}\)

  |x-1|        = \(\dfrac{3}{2}\)

\(\left[{}\begin{matrix}x-1=\dfrac{3}{2}\\x-1=-\dfrac{3}{2}\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=\dfrac{3}{2}+1\\x=-\dfrac{3}{2}+1\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)

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

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

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

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

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

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

                     \(x\) = -4

d, \(\dfrac{x+2}{3}\) = \(\dfrac{27}{x+2}\)

(x+2)² = 27.3

(x+2) =9²

\(\left[{}\begin{matrix}x+2=9\\x+2=-9\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=7\\x=-11\end{matrix}\right.\)

x=1/6

x=1/4

a) x = 1/6

b) x = 1/4

HT

a) 2/3 + x = 5/6

X = 5/6 - 2/3

X = 1/6

b)  x : 5/6 = 3/10

X = 5/6 x 3/10

X = 17/15

a)13,2 - x = -4,3

=> x = 13,2 - ( -4,3)

=> x = 17,5

b)x phần 3 = 20 phần 15 

\(\dfrac{x}{3}=\dfrac{20}{15}=>20.3=x.15=>60=x.15=>x=60:15=>x=4\)

c) 2 phần 3 - 1 phần 3 x = -5 phần 3 + 1 phần 2

Mong bạn viết lại đề giúp mình

d) x - 3 phần 5 = -7 phần 10

\(\dfrac{x-3}{5}=\dfrac{-7}{10}=>5.-7=\left(x-3\right).10=>-35=\left(x-3\right).10=>x-3=-35:10=>x-3=\text{-3,5}=>x=\text{-3,5}+3=>x=6,5\)

`a)`

`13,2-x=-4,3`

`x=13,2-(-4,3)`

`x=17,5`

Vậy `x=17,5`

__________________________

`b)`

\(\dfrac{x}{3}=\dfrac{20}{15}\)

`=>x` `xx15=20xx3`

`x` `xx15=60`

`x=60:15`

`x=4`

Vậy `x=4`

__________________________

`c)`

\(\dfrac{2}{3}-\dfrac{1}{3x}=\dfrac{-5}{3}+\dfrac{1}{2}\\ \dfrac{2}{3}-\dfrac{1}{3x}=-\dfrac{7}{6}\\ \dfrac{1}{3x}=\dfrac{2}{3}-\left(-\dfrac{7}{6}\right)\\ \dfrac{1}{3x}=\dfrac{11}{6}\\ \Rightarrow1\times6=11\times3\times x\\ 6=33\times x\\ x=5,5\)

Vậy `x=5,5`

__________________________

`d)`

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

`=>(x-3)xx10=5xx(-7)`

`(x-3)xx10=-35`

`x-3=-35:10`

`x-3=-3,5`

`x=-6,5`

Vậy `x=-6,5`

`@An`

a) \(\dfrac{x.2}{-15}=\dfrac{-5}{3}\)

\(\dfrac{x.2}{-15}=\dfrac{25}{-15}\)

x.2=25

x=12,5

b) \(\dfrac{x-1}{-12}=\dfrac{-3}{x-1}\)

(x-1)²=-3.(-12)

(x-1)²=36 

⇒(x-1)²\(\Rightarrow\left[{}\begin{matrix}x-1=6\\x-1=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=7\\x=-5\end{matrix}\right.\)

\(a,x-\dfrac{5}{7}=\dfrac{3}{5}\times\dfrac{1}{2}\)

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

\(x=\dfrac{3}{10}+\dfrac{5}{7}\)

\(x=\dfrac{21}{70}+\dfrac{50}{70}\)

\(x=\dfrac{71}{70}\)

\(Vayx=\dfrac{71}{70}\)

\(b,x\times\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{3}{4}\)

\(x\times\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{6}{8}\)

\(x\times\dfrac{2}{3}=\dfrac{11}{8}\)

\(x=\dfrac{11}{8}:\dfrac{2}{3}\)

\(x=\dfrac{11}{8}\times\dfrac{3}{2}\)

\(x=\dfrac{33}{16}\)

\(Vayx=\dfrac{33}{16}\)

`x+2/5=4/3`

`=>x=4/3-2/5`

`=> x= 20/15 -6/15`

`=>x= 14/15`

__

`x : 3/2 =2 xx 1/5`

`=> x : 3/2= 2/5`

`=> x= 2/5 xx 3/2`

`=> x= 6/10`

`=>x= 3/5`

__

Bài `5` này có `1` chút lạ ạ 

3/5 * x -1/2 = 1/5

giúp mình nhá mình đang cần gấp 

a) Ta có: \(\left(2x-3\right)-\left(x-5\right)=\left(x+2\right)-\left(x-1\right)\)

\(\Leftrightarrow2x-3-x+5=x+2-x+1\)

\(\Leftrightarrow x+2=3\)

hay x=1

Vậy: x=1

b) Ta có: \(2\left(x-1\right)-5\left(x+2\right)=-10\)

\(\Leftrightarrow2x-2-5x-10=-10\)

\(\Leftrightarrow-3x=-10+10+2=2\)

hay \(x=-\dfrac{2}{3}\)

Vậy: \(x=-\dfrac{2}{3}\)

a, (2x - 3) - (x - 5) = (x + 2) - (x - 1)

 2x - 3 - x + 5 = x + 2 - x + 1

(2x - x) + (-3 + 5) = (x - x) + (2 + 1)

x + 2 = 3

x = 1