\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)=20\)

\(3x+6=20\)

\(\Leftrightarrow3x=14\)

\(\Leftrightarrow x=\frac{14}{3}\)

Vậy \(x=\frac{14}{3}\)

   (x+1) + (x+2) + (x+3) = 3x + 6 = 20

=> 3x + 6 =20

      3x       = 20 - 6

      3x       = 14

       x        = 14/3

(x + 1) + (x+2) + (x+3) = 20 

x + 1 + x + 2 + x + 3 = 20 

=> (x + x + x) + (1 + 2 + 3) = 20

=> 3x + 6 = 20 

=> 3x = 20 - 6 

=> 3x = 14 

=> x = 14 : 3 = 14/3 

Vậy x = 14/3

( x + 1 ) + ( x + 2 ) + ( x + 3 ) = 20

( x + x + x ) + ( 1 + 2 + 3 ) = 20

x * 3 + 6 = 20

x * 3 = 20 - 6

x * 3 = 14

Hình như đề sai bạn ạ , mình không chắc lắm .

Cách khác,khó hơn chút.

\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)=20\)

\(\Leftrightarrow3\left(x+1\right)+1+2=20\)

\(\Leftrightarrow3\left(x+1\right)=17\Leftrightarrow x+1=\frac{17}{3}\Leftrightarrow x=\frac{14}{3}\)

(x+1)+(x+2)+(x+3)=20

x+(1+2+3)=20

x+6=20

x    =20-6

x    =14

\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)=20\\ \Leftrightarrow3\left(x+1\right)+1+2=20\)

\(\Leftrightarrow3\left(x+1\right)=17\Leftrightarrow x+1=\frac{17}{3}\Leftrightarrow x=\frac{14}{3}\)

(x + 1) + (x + 2) + (x + 3) = 20 

=>x + 1 + x + 2 + x + 3 = 20

x + x + x + 1 + 2 + 3 = 20

3 * x = 20 - 6

x = 14/3

\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)=20\)

\(x+1+x+2+x+3=20\)

\(x\cdot3+\left(1+2+3\right)=20\)

\(x\cdot3+6=20\)

\(x\cdot3=20-6\)

\(x\cdot3=14\)

\(x=14:3\)

\(x=\frac{14}{3}\)