2 câu trả lời
`\frac{x+1}{2018}-\frac{x+2}{2017}=\frac{x+3}{2016}+1`
`<=>\frac{x+1}{2018}+1-\frac{x+2}{2017}-1=\frac{x+3+2016}{2016}`
`<=>\frac{x+1+2018}{2018}-\frac{x+2+2017}{2017}=\frac{x+2019}{2016}`
`<=>\frac{x+2019}{2018}-\frac{x+2+2017}{2017}-\frac{x+2019}{2016}=0`
`<=>(x+2019)(1/2018-1/2017-1/2016)=0`
`=>x+2019=0(`Vì `1/2018-1/2017-1/2016\ne0)`
`<=>x=-2019`
Vậy `S={-2019}`