\(\dfrac{x+1}{x^2+x+1}-\dfrac{x-1}{x^2-x+1}=\dfrac{2\left(x+2\right)^2}{\left(x^2-1\right)\left(x^4+x^2+1\right)}\)
\(\Leftrightarrow\dfrac{x^3+1-x^3+1}{x^4+x^2+1}=\dfrac{2\left(x+2\right)^2}{\left(x^2-1\right)\left(x^4+x^2+1\right)}\)
\(\Leftrightarrow2\left(x^2-1\right)=2\left(x+2\right)^2\)
\(\Leftrightarrow2x^2+8x+8=2x^2-2\)
=>8x=-10
hay x=-5/4