\(\Leftrightarrow2x^3-2x+x^2-1-4x^2+2x+2=0\)
\(\Leftrightarrow2x^3-3x^2+1=0\)
\(\Leftrightarrow2x^3-2x^2-x^2+1=0\)
\(\Leftrightarrow2x^2\left(x-1\right)-\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x^2-x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x^2-2x+x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)^2\left(2x+1\right)=0\)
=>x=1 hoặc x=-1/2
\(\left(2x+1\right)\left(x^2-1\right)=4x^2-2x-2\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)\left(x+1\right)=4x^2-4x+2x-2\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)\left(x+1\right)=4x\left(x-1\right)+2\left(x-1\right)\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)\left(x+1\right)=\left(4x+2\right)\left(x-1\right)\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)\left(x+1\right)=2\left(2x+1\right)\left(x-1\right)\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)\left(x+1\right)-2\left(2x+1\right)\left(x-1\right)=0\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)\left(x+1-2\right)=0\\ \Leftrightarrow\left(2x+1\right)\left(x-1\right)^2=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=1\end{matrix}\right.\)
