\(x^3-x^2+2=x^3+1-\left(x^2-1\right)=\left(x+1\right)\left(x^2-x+1\right)-\left(x+1\right)\left(x-1\right)=\left(x+1\right)\left(x^2-x+1-x-1\right)=\left(x+1\right)\left(x^2-2x\right)=x\left(x+1\right)\left(x-2\right)\)
À mình nhầm : \(x^3-x^2+2=0\)
\(\Leftrightarrow x\left(x+1\right)\left(x-2\right)=0\) ( phân tích mk phân tích ở dưới r nhé )
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\\x=2\end{matrix}\right.\)
=>\(x^3+x^2-2x^2-2x+2x+2=0\)
\(x^2\left(x+1\right)-2x\left(x+1\right)+2\left(x+1\right)=0\)
\(\left(x+1\right)\left(x^2-2x+2\right)=0\)
Vì \(x^2-2x+2=x^2-2x+1+1=\left(x-1\right)^2+1\ge1>0\)
=> x+1=0 hay x=-1
