\(6x^4-x^3-7x^2+x+1=0\)
\(\Leftrightarrow6x^4-6x^2-\left(x^3-x\right)-\left(x^2-1\right)=0\)
\(\Leftrightarrow6x^2\left(x^2-1\right)-x\left(x^2-1\right)-\left(x^2-1\right)=0\)
\(\Leftrightarrow\left(x^2-1\right)\left(6x^2-x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x^2-1=0\\6x^2-x-1=0\end{matrix}\right.\)
Bấm máy

