x-1/2018 + x-2/2017 + x-3/2016 + ... + x-2018/1 = 2018
(x-1-2018/2018) + (x-2-2017/2017) + (x-3-2016/2016) + ... + (x-2018-1/1) = 0
x-2019/2018 + x-2019/2017 + x-2019/2016 + ... + x-2019/1 = 0
(x-2019)(1/2018 + 1/2017 + 1/2016 + ... + 1/1)=0
=> x-2019=0
=> x=2019
Vậy x=2019.