\(\Leftrightarrow\left\{{}\begin{matrix}x\ne\left\{1,-2\right\}\\\dfrac{x^2-x^3}{\left(x-1\right)\left(x^2+x+1\right)}+\dfrac{\left(x^2+x+1\right)}{x+2}=0\end{matrix}\right.\)
\(\Leftrightarrow\dfrac{1-x^2}{x^2+x+1}+\dfrac{x^2+x+1}{x+2}=0\Leftrightarrow\left(x^4+2x^3+3x^2+2x+1\right)-\left(x^3+2x^2-x-2\right)\)
\(\Leftrightarrow x^4+x^3+x^2+3x+3=0\)
\(\Leftrightarrow\left(x^2+\dfrac{x}{2}-1\right)^2+\dfrac{11x^2}{4}+4x+2=0\)
\(\Leftrightarrow\left(x^2+\dfrac{x}{2}-1\right)^2+2\left(x+2\right)^2+\dfrac{3}{4}x^2=0\)
dấu đẳng thức không đồng thời => Vô nghiệm
Đúng 0
Bình luận (0)
