Thu gọn và tính A=(1+1/2).(1+1/3).(1+1/4).(1+1/5)...(1+1/2019) Tham khảo câu trả lời từ Trợ lý ảo Lazi Để tính giá trị của A, ta có thể thấy mẫu số của từng phân số trong dãy (1 + 1/2), (1 + 1/3), (1 + 1/4), ..., (1 + 1/2019) đều là 2, 3, 4, ..., 2019 tương ứng. Vì vậy, ta có thể viết lại dãy trên dưới dạng tổng quát là (1 + 1/n), với n chạy từ 2 đến 2019. Khi đó, ta có: A = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/4) . ... . (1 + 1/2019) = (1 + 1/2) . (1 + 1/3) . (1 + 1/