Đáp án + giải thích các bước giải:
`x^3-7x+6=0`
`->x^3-x^2+x^2-x-6x+6=0`
`->x^2(x-1)+x(x-1)-6(x-1)=0`
`->(x^2+x-6)(x-1)=0`
`->`\(\left[ \begin{array}{l}x^2+x-6=0\\x-1=0\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x^2+2. \dfrac{1}{2}x+\dfrac{1}{4}-\dfrac{25}{4}=0\\x=1\end{array} \right.\)
`->`\(\left[ \begin{array}{l}(x+\dfrac{1}{2})^2=\dfrac{25}{4}\\x=1\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x+\dfrac{1}{2}=\dfrac{5}{2}\\x+\dfrac{1}{2}=\dfrac{-5}{2}\\x=1\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x=2\\x=-3\\x=1\end{array} \right.\)
