Bất phương trình \(\left|\dfrac{x^2-3x+1}{x^2+x+1}\right|< 3\) có nghiệm là
\(\left[\begin{matrix}x< \frac{3-\sqrt{5}}{2}\\x>\frac{3+\sqrt{5}}{2}\end{matrix}\right.\).\(\left[\begin{matrix}x< \frac{-3-\sqrt{5}}{2}\\x>\frac{-3+\sqrt{5}}{2}\end{matrix}\right.\).\(\left[\begin{matrix}x< \frac{5-\sqrt{3}}{2}\\x>\frac{5+\sqrt{3}}{2}\end{matrix}\right.\).\(\left[\begin{matrix}x< \frac{-5-\sqrt{3}}{2}\\x>\frac{-5+\sqrt{3}}{2}\end{matrix}\right.\).Hướng dẫn giải:
