\(\left(x-7\right)\left(x+3\right)=0\)\(\Leftrightarrow\left[{}\begin{matrix}x-7=0\\x+3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-3\end{matrix}\right.\)Vậy \(S=\left\{7;-3\right\}\)Câu trả lời: \(\left(x-7\right)\left(x+3\right)=0\)\(\Leftrightarrow\left[{}\begin{matrix}x-7=0\\x+3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-3\end{matrix}\right.\)Vậy \(S=\left\{7;-3\right\}\)