Question

tìm x biết rằng 17 chia hết cho ( x-1 ) và ( x-1 ) chia hết cho 17

 

Answer 1

\(17⋮\left(x-1\right)\Rightarrow\left(x-1\right)\inƯ\left(17\right)=\left\{1;-1;17;-17\right\}\)

Mà \(\left(x-1\right)⋮17\)

\(\Rightarrow\left(x-1\right)\in\left\{17;-17\right\}\)

\(\Rightarrow x\in\left\{18;-16\right\}\)

Answer 2

\(17⋮\left(x-1\right)\\ \Rightarrow x-1\inƯ\left(17\right)=\left\{-17;-1;1;17\right\}\)

Mà \(x-1⋮17\Rightarrow x-1\in\left\{-17;17\right\}\)

\(\Rightarrow x\in\left\{-16;18\right\}\)

Answer 3

\(\left\{{}\begin{matrix}17⋮x-1\\x-1⋮17\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x-1\in\left\{1;-1;17;-17\right\}\\x-1\in\left\{17;34;...\right\}\end{matrix}\right.\)

hay \(x\in\left\{18;-16\right\}\)