How is -1 written in $p$-adics?
![](https://cdn.mathpix.com/cropped/2024_05_10_76fb8a4d30ed0b9c3f11g-353.jpg?height=160&width=651&top_left_y=316&top_left_x=607)

From this, we deduce that in $p$-adics, $-1=\ldots(p-1) \ldots(p-1)$.

Subtraction also works similarly to what we usually use.