Đáp án + Giải thích các bước giải:
`(x+1)/(2018)+(x+2)/(2017)+(x+3)/(2016)=(3x+12)/(2015)`
`=>(x+1)/(2018)+(x+2)/(2017)+(x+3)/(2016)=(x+4)/(2015)+(x+4)/(2015)+(x+4)/(2015)`
`=>((x+1)/(2018)+1)+((x+2)/(2017)+1)+((x+3)/(2016)+1)=((x+4)/(2015)+1)+((x+4)/(2015)+1)+((x+4)/(2015)+1)`
`=>((x+1)/(2018)+(2018)/(2018))+((x+2)/(2017)+(2017)/(2017))+((x+3)/(2016)+(2016)/(2016))=((x+4)/(2015)+(2015)/(2015))+((x+4)/(2015)+(2015)/(2015))+((x+4)/(2015)+(2015)/(2015))`
`=>(x+2019)/(2018)+(x+2019)/(2017)+(x+2019)/(2006)=(x+2019)/(2015)+(x+2019)/(2015)+(x+2019)/(2015)`
`=>(x+2019)/(2018)+(x+2019)/(2017)+(x+2019)/(2006)-(x+2019)/(2015)-(x+2019)/(2015)-(x+2019)/(2015)=0`
`=>(x+2019)((1)/(2018)+(1)/(2017)+(1)/(2016)-(1)/(2015)-(1)/(2015)-(1)/(2015))=0`
Vì `(1)/(2018)+(1)/(2017)+(1)/(2016)-(1)/(2015)-(1)/(2015)-(1)/(2015)\ne0`
`=>x+2019=0`
`=>x=-2019`
