so sánh: 2019/2019 . 2020 và 2020/2020 . 2021 05/11/2021 Bởi Margaret so sánh: 2019/2019 . 2020 và 2020/2020 . 2021
Ta có: $\dfrac{2019}{2019.2020}=\dfrac{1}{2020}$ $\dfrac{2020}{2020.2021}=\dfrac{1}{2021}$ Vì $\dfrac{1}{2020} > \dfrac{1}{2021}$ $⇒$ $\dfrac{2019}{2019.2020}>\dfrac{2020}{2020.2021}$ Vậy $\dfrac{2019}{2019.2020}>\dfrac{2020}{2020.2021}$ Bình luận
Ta có:
$\dfrac{2019}{2019.2020}=\dfrac{1}{2020}$
$\dfrac{2020}{2020.2021}=\dfrac{1}{2021}$
Vì $\dfrac{1}{2020} > \dfrac{1}{2021}$ $⇒$ $\dfrac{2019}{2019.2020}>\dfrac{2020}{2020.2021}$
Vậy $\dfrac{2019}{2019.2020}>\dfrac{2020}{2020.2021}$
Đáp án:
Giải thích các bước giải: