Question

Tìm x biết: 

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

Answer 1

`1/3x+2/5(x+1)=0`

`1/3x+2/5x+2/5=0`

`11/15x=-2/5`

`x=-6/11`

Vậy `x=-6/11`

Answer 2

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

\(\dfrac{1}{3}\cdot x+\dfrac{2}{5}\cdot x+\dfrac{2}{5}\cdot1\)=0

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

\(x\cdot\dfrac{2}{5}+\dfrac{2}{5}=0\)

\(\dfrac{2}{5}\cdot\left(x+1\right)=0\)

x+1=0

=>x=-1

vậy x=-1

 

Answer 3

1/3.x+2/5.(x+1)=0

1/3.x+2/5.x+2/5=0

(1/3+2/5).x+2/5=0

(5/15+6/15).x+2/5=0

11/15.x+2/5=0

11/15.x=0-2/5

11/15.x= -2/5

x= -2/5 : 11/15

x= -2/5 . 15/11

x= -30/55 = -6/11

Vậy x= -6/11

Answer 4

\(\dfrac{1}{3}.x+\dfrac{2}{5}.\left(x+1\right)=0\) 

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

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

                  \(x.\dfrac{11}{15}=\dfrac{-2}{5}\) 

                        \(x=\dfrac{-2}{5}:\dfrac{11}{15}\) 

                        \(x=\dfrac{-6}{11}\)