![](https://i.imgur.com/IZhPbSt.jpg)
[理工] 105台大電機丙 離散
![](https://i.imgur.com/IZhPbSt.jpg)
想問第一行的第二個的式子是怎麼轉換的
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推
02/11 21:50, , 1F
02/11 21:50, 1F
→
02/11 22:12, , 2F
02/11 22:12, 2F
推
02/12 06:51, , 3F
02/12 06:51, 3F
![](https://i.imgur.com/sRjffvD.jpg)