Tính bằng cách hợp lí nhất: 1919 / 2323 x 464646 / 747474 x 37 / 19

* Hướng dẫn giải

$$\begin{gathered} \frac{1919}{2323}\mathit{\times }\frac{464646}{747474}\mathit{\times }\frac{37}{19} \\ =\frac{19}{23}\mathit{\times }\frac{46}{74}\mathit{\times }\frac{37}{19} \\ =\frac{19\mathit{\times }46\mathit{\times }37}{23\mathit{\times }74\mathit{\times }19} \\ =\frac{46\mathit{\times }37}{23\mathit{\times }74} \\ =\frac{23\mathit{\times }2\mathit{\times }37}{23\mathit{\times }37\mathit{\times }2} \\ =1 \end{gathered}$$