`(x+2)/15 + (x+2)/16 + (x+2)/17 = (x+2)/18 + (x+2)/19`
`<=> (x+2)/15 + (x+2)/16 + (x+2)/17 - (x+2)/18 - (x+2)/19 = 0`
`<=> (x+2)(1/15 + 1/16 + 1/17 - 1/18 - 1/19) = 0`
Dễ thấy `1/15 + 1/16 + 1/17 - 1/18 - 1/19≠0`
`=> x + 2 = 0`
`<=> x = -2`
Vậy `x = -2`