Giải phương trình (x - 2022)^3 + (x - 2023)^3 = (2x - 4045)^3
Câu hỏi:
Giải phương trình (x – 2022)3 + (x – 2023)3 = (2x – 4045)3.
Trả lời:
(x – 2022)3 + (x – 2023)3 = (2x – 4045)3
⇔ (x – 2022)3 + (x – 2023)3 = [(x – 2022) + (x – 2023)]3
⇔ (x – 2022)3 + (x – 2023)3 = (x – 2022)3 + 3(x – 2022)2(x – 2023) + 3(x – 2022)(x – 2023)2 + (x – 2023)3
⇔ 3(x – 2022)2(x – 2023) + 3(x – 2022)(x – 2023)2 = 0
⇔ 3(x – 2022)(x – 2023)(x – 2022 + x – 2023) = 0
⇔ (x – 2022)(x – 2023)(2x – 4045) = 0
⇔ [x−2022=0x−2023=02x−4045=0
⇔ [x=2022x=2023x=40452
Vậy x ∈ {2022;2023;40452}.