`(x-1)(2x+7)(x^2+2)=0`\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\2x+7=0\\x^2+2=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=1\\2x=-7\\x^2=-2\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{7}{2}\\x\in\varnothing\end{matrix}\right.\)Vậy pt có nghiệm \(S=\left\{1;-\dfrac{7}{2}\right\}\)Câu trả lời: `(x-1)(2x+7)(x^2+2)=0`\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\2x+7=0\\x^2+2=0\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=1\\2x=-7\\x^2=-2\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{7}{2}\\x\in\varnothing\end{matrix}\right.\)Vậy pt có nghiệm \(S=\left\{1;-\dfrac{7}{2}\right\}\)