Nguyễn Thị Quỳnh Linh
Ta có :
\(\left|x+1\right|\ge0\)
\(\left|x+2\right|\ge0\)
\(\left|x+3\right|\ge0\)
\(\Rightarrow\left|x+1\right|+\left|x+2\right|+\left|x+3\right|\ge0\)
\(\Rightarrow4x\le0\)
Mà 4 > 0
=> x > 0
=> x + 1 + x + 2 + x + 3 = 4x (phá trị uyệt đối vì x dương)
=> 3x + 6 = 4x
=> 4x - 3x = 6
=> x = 6
\(\left|x+1\right|+\left|x+2\right|+\left|x+3\right|=4x\)
\(3x+6=4x\Rightarrow x=6\)
| x + 1 | \(\ge\)0 ; | x + 2 | \(\ge\)0 ; | x + 3 | \(\ge\)0
=> | x + 1 | + | x + 2 | + | x + 3 | \(\ge\)0
=> 4x \(\ge\)=> x \(\ge\)0
=> x+1 + x+2 + x +3= 4x
=> 3x + 6 = 4x
=> x = 6
Vậy....
