=> cái vế  trong ngoặc là 0.

rồi bạn làm tiếp nha

\(\dfrac{-12}{25}.\left(\dfrac{3}{4}-x+\dfrac{6}{-11}-\dfrac{5}{6}\right)=0\)

\(\dfrac{3}{4}-x+\dfrac{-6}{11}-\dfrac{5}{6}=0\)

\(\dfrac{3}{4}-x+\dfrac{-91}{66}=0\)

\(\dfrac{3}{4}-x=0-\left(\dfrac{-91}{66}\right)\)

\(\dfrac{3}{4}-x=\dfrac{91}{66}\)

\(x=\dfrac{-83}{132}\)

a: Ta có: \(-\dfrac{12}{25}\cdot\left(\dfrac{3}{4}-x+\dfrac{6}{-11}-\dfrac{5}{6}\right)=0\)

\(\Leftrightarrow x+\dfrac{83}{132}=0\)

hay \(x=-\dfrac{83}{132}\)

- 25 - ( x + 5 ) = 415 + 5( x - 83 )

- 25 - x-5= 415+ 5x -415

- 30-x = 415 -415 +5x

-30-x = 5x

-30= x+ 5x

-30 = 6x

-30:6= x

-5 = x

Vậy...

-25 - ( x + 5 ) = 415 + 5( x - 83 )

     -25 - x - 5 = 415 + 5x - 415

 ( -25 - 5 ) - x = ( 415 - 415 ) +5x

          -30 - x = 5x

               -30 = 5x + x

               -30 = 6x

                  x = ( -30) :6

                  * = -5

a. 90 : X = 6

           X = 15

b. X : 5 = 83

    X  = 415

x = 2

x-7 = -5

<=> x = -5+7

<=> x = 2

Vậy x =2

x=2

\(x^2\left(x-5\right)+x-5=0\)

\(\Rightarrow x^2\left(x-5\right)+\left(x-5\right)=0\)

\(\Rightarrow\left(x-5\right)\left(x^2-1\right)=0\)

\(\Rightarrow\left(x-5\right)\left(x-1\right)\left(x+1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-5=0\\x-1=0\\x+1=0\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x=1\\x=-1\end{matrix}\right.\)

\(x^2\left(x-5\right)+x-5=0\)

\(\Leftrightarrow x-5=0\)

hay x=5

`x+4/5=45/5-36/35`

`x+4/5=279/35`

`x=251/34`

=>x-3/4=2

hay x=11/4

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

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

\(x=\dfrac{11}{4}\)

x - 3/4 = 8/5 x 5/4

x - 3/4 =  2

       x  = 2 + 3/4

       x  = 11/4

vậy x =...

băng băng nè cậu có buồn vì - điểm ko