Question

Tìm x biết: (3x+6)+(x-9)=x+12

 

Answer 1

(3x+6)+(x-9)=x+12

3x+6+x-9=x+12

3x+x-x=12-6-9

3x=-3

  x=-3:3

  x=-1

vậy x=-1

Answer 2

(3x+6)+(x-9)=x+12

<=> 3x+6+x-9=x+12

<=> 4x-3=x+12

<=> 4x-x=12+3

<=> 3x=15

<=>x=5

Answer 3

\(\left(3x+6\right)+\left(x-9\right)=x+12\)

\(3x+6+x-9=x+12\)

\(\Rightarrow3x-x-x=12-6+9\)

\(\Rightarrow x=15\)

vậy\(=15\)

Học tốt

Answer 4

\(\left(3x+6\right)+\left(x-9\right)=x+12\)

\(3x+6+x-9=x+12\)

\(4x-3=x+12\)

\(4x-x=12+3\)

\(3x=15\)

\(x=5\)

Vậy\(x=5\)