Question

Determinati x apartine lui Z stiin d ca 5 supra 1-x apartine lui Z .va rog din tot sufletul ajutati-ma plsss

Answer 1

x∈ℤ,   5/(1-x)∈ℤ,   x=?

$\it \dfrac{5}{1-x}\in\mathbb{Z} \Rightarrow 1-x|5 \Rightarrow 1-x\in D_5 \Rightarrow x-1\in D_5 \Rightarrow\\ \\ \\ \Rightarrow x-1 \in\{-5,\ -1,\ 1,\ 5\}|_{+1} \Rightarrow x\in\{-4,\ 0,\ 2,\ 6\}$