`(2020-x)^3+(2021-x)^3+(2x-4041)^3=0`
`⇔(2020-x)^3+(2021-x)^3-(2020-x+2021-x)^3=0`
`⇔(2020-x)^3+(2021-x)^3-[(2020-x)+(2021-x)]^3=0`
`⇔(2020-x)^3+(2021-x)^3-[(2020-x)^3+3(2020-x)^2(2021-x)+3(2020-x)(2021-x)^2+(2021-x)^3=0`
`⇔(2020-x)^3+(2021-x)^3-(2020-x)^3-3(2020-x)^2(2021-x)-3(2020-x)(2021-x)^2-(2021-x)^3]=0`
`⇔-3(2020-x)^2(2021-x)-3(2020-x)(2021-x)^2=0`
`⇔-3(2020-x)(2021-x)(2020-x+2021-x)=0`
`⇔3(2020-x)(2021-x)(-2020+x-2021+x)=0`
`⇔3(2020-x)(2021-x)(2x-4041)=0`
`⇔` \(\left[ \begin{array}{l}2020-x=0\\2021-x=0\\2x-4041=0\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x=2020\\x=2021\\x=\dfrac{4041}{2}\end{array} \right.\)
Vậy phương trình có tập nghiệm `S={2020;2021;{4041}/2}`
