Đáp án:
`x=-2`
Giải thích các bước giải:
`(x+1)/19+(x+3)/17+(x+6)/14=-3`
`=>(x+1)/19+(x+3)/17+(x+6)/14+3=0`
`=>((x+1)/19+1)+((x+3)/17+1)+((x+6)/14+1)=0`
`=>((x+1)/19+19/19)+((x+3)/17+17/17)+((x+6)/14+14/14)=0`
`=>(x+1+19)/19+(x+3+17)/17+(x+6+14)/14=0`
`=>(x+20)/19+(x+20)/17+(x+20)/14=0`
`=>(x+2)(1/19+1/17+1/14)=0`
`=>x+2=0` (vì `1/19+1/17+1/14\ne0`)
`=>x=-2`
Vậy `x=-2`