Có |x+1/2| \(\ge\)0 với mọi x
|x+1/3| \(\ge\)0 với mọi x
|x+1/4| \(\ge\)0 với mọi x
=>4x\(\ge\)0
=>x\(\ge\)0
Với x\(\ge\)0
=>|x+1/3|=x+1/3
|x+1/2|=x+1/2
|x+1/4|=x+1/4
=>x+1/2+x+1/3+x+1/4=4x
=>3x+ 13/12=4x
=>3x-4x=-13/12
=>-x=-13/12
=>x=13/12
Vậy x=13/12