Đáp án: $ x = - 2020$
Giải thích các bước giải:
$ \dfrac{x + 1}{2019} + \dfrac{x + 2}{2018} - \dfrac{x}{2016} = \dfrac{x + 3}{2017} + \dfrac{1}{504}$
$ ⇔ \dfrac{x + 1}{2019} - \dfrac{x + 3}{2017} + \dfrac{x + 2}{2018} - \dfrac{x}{2016} - \dfrac{4}{2016} = 0$
$ ⇔ (\dfrac{x + 1}{2019} - \dfrac{x + 3}{2017}) + (\dfrac{x + 2}{2018} - \dfrac{x + 4}{2016}) = 0$
$ ⇔ \dfrac{2017x + 2017 - 2019x - 3.2019}{2017.2019} + \dfrac{2016x + 2.2016 - 2018x - 4.2018}{2016.2018} = 0$
$ ⇔ \dfrac{- 2(x + 2020)}{2017.2019} + \dfrac{- 2(x + 2020)}{2016.2018} = 0$
$ ⇔ - 2(x + 2020)(\dfrac{1}{2017.2019} + \dfrac{1}{2016.2018}) = 0$
$ ⇔ x + 2020 = 0 ⇔ x = - 2020$
