Vì \(\text{x - 7}\) \(⋮\) \(\text{x + 6}\)
\(\Rightarrow\) \(\text{x + 6 -13}\) chia hết cho \(\text{x + 6}\)
Mà \(\text{x + 6}\) chia hết cho \(\text{x + 6}\)
\(\Rightarrow\) \(\text{13}\) chia hết cho \(\text{x + 6}\)
\(\Rightarrow\) \(\text{x + 6 ∈}\) \(\left\{\text{±1 ; ± 13}\right\}\)
\(\Rightarrow\) \(\text{x ∈}\) \(\left\{\text{-7 ; -5 ; -19 ; 7}\right\}\)