`(2024-x)^3 + (2026-x)^3 + (2x-4050)^3 =0 (1)`

Đặt `{(m=2024-x),(n=2026-x):}`

`(1)=>m^3 + n^3 - (m+n)^3 =0`

`<=> m^3 + n^3 - m^3 -n^3 -3m^2 n - 3mn^2 =0`

`<=>-3m^2 n - 3mn^2 =0`

`<=>-3mn(m + n)=0`

`<=>mn(m+n)=0`

`=>(2024-x)(2026-x)(2x-4050)=0`

`<=>[(2024-x=0),(2026-x=0),(2x=4050):}`

`<=>[(x=2024),(x=2026),(x=2025):}`

Vậy `S={2024;2025;2026}`.