Câu hỏi: b) (x + y)(x2 – xy + y2); Trả lời: b) (x + y)(x2 – xy + y2) = x . x2 – x . xy + x . y2 + y . x2 – y . xy + y . y2 = x3 – x2y + xy2 + x2y – xy2 + … Link Hoc va de thi 2021