a) x2y - xy2 - 5x + 5y = xy(x - y) - 5(x - y) = (xy - 5)(x - y)b) x2 + 8x - y2 + 16 = (x2 + 8x + 16) - y2 = (x + 4)2 - y2 = (x + y + 4)(x - y + 4)c) x2 - 7x + 10 = x2 - 2x - 5x + 10 = x(x - 2) - 5(x - 2) = (x - 5)(x - 2)Câu trả lời: a) x2y - xy2 - 5x + 5y = xy(x - y) - 5(x - y) = (xy - 5)(x - y)b) x2 + 8x - y2 + 16 = (x2 + 8x + 16) - y2 = (x + 4)2 - y2 = (x + y + 4)(x - y + 4)c) x2 - 7x + 10 = x2 - 2x - 5x + 10 = x(x - 2) - 5(x - 2) = (x - 5)(x - 2)