so sánh 2019/2029 và 2024/2025 ( so sánh 8 cách cho mình nha )

Hiện tại chỉ nghĩ được $5$ cách . 

$C1$ . 

$\dfrac{2019}{2020} ≈ 0,999504….$

$\dfrac{2024}{2025} ≈ 0,999506….$

$⇒ \dfrac{2019}{2020} < \dfrac{2024}{2025}$

$C2$

$\dfrac{2019}{2020} = \dfrac{2019 \times 2025}{2020 \times 2025}=\dfrac{4078380}{2020 \times 2025}$

$\dfrac{2024}{2025} = \dfrac{2024 \times 2020}{2020 \times 2025}= \dfrac{4088480}{2020 \times 2025}$

Vì : $\dfrac{4088480}{2020 \times 2025} > \dfrac{4078380}{2020 \times 2025}$

$⇒ \dfrac{2019}{2020} < \dfrac{2024}{2025}$

$C3$.

$\dfrac{2019}{2020} – \dfrac{2024}{2025} = \dfrac{2025 \times 2019 – 2020 \times 2024}{2020 \times 2025} = \dfrac{-5}{2020 \times 2025}$ là số âm nên $\dfrac{2019}{2020} < \dfrac{2024}{2025}$

$⇒$ $\dfrac{2019}{2020} < \dfrac{2024}{2025}$

$C4$.

$\dfrac{2024}{2025} – \dfrac{2019}{2020}  = \dfrac{2020 \times 2024 – 2025 \times 2019}{2020 \times 2025} = \dfrac{5}{2020 \times 2025}$ là số dương nên $\dfrac{2019}{2020} < \dfrac{2024}{2025}$

$⇒$ $\dfrac{2019}{2020} < \dfrac{2024}{2025}$

$C5$. $\dfrac{2019}{2020} = 1 – \dfrac{1}{2020}$

          $\dfrac{2024}{2025} = 1- \dfrac{1}{2025}$

Vì : $\dfrac{1}{2020} > \dfrac{1}{2025}$

$⇒$ $\dfrac{2019}{2020} < \dfrac{2024}{2025}$