`|x+1/2|+|x+1/6|+|x+1/20|+.........+|x+1/110|=11x`
Vì `VT=VP≥0⇒x≥0`
`⇒(x+x+............+x)+(1/2+1/6+1/12+..........+1/110)=11x`
`⇒1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90+1/110=x`
`⇒x=1/(1.2)+1/(2.3)+1/(3.4)+...........+1/(10.11)`
`⇒x=1-1/11=10/11`
Vậy `x=10/11`