Câu hỏi: b) (3x + 2y)3 + (3x – 2y)3. Trả lời: b) (3x + 2y)3 + (3x – 2y)3 = (3x)3 + 3 . (3x)2 . 2y + 3 . 3x . (2y)2 + (2y)3 + (3x)3 – 3 . (3x)2 . 2y – 3 . 3x . (2y)2 + (2y)3 = (3x)3 + … Link Hoc va de thi 2021