\(\frac{x+2}{2\text{x}-4}-\frac{4\text{x}}{x^2-4}\)                      MTC: 2(x-2)(x+2)

= \(\frac{x+2}{2\left(x-2\right)}-\frac{4\text{x}}{\left(x-2\right)\left(x+2\right)}\)

= \(\frac{\left(x+2\right)^2}{2\left(x-2\right)\left(x+2\right)}-\frac{8\text{x}}{2\left(x-2\right)\left(x+2\right)}\)

= \(\frac{\left(x+2\right)^2-8\text{x}}{2\left(x-2\right)\left(x+2\right)}\)

= \(\frac{x^2+4\text{x}+4-8\text{x}}{2\left(x-2\right)\left(x+2\right)}\)

= \(\frac{x^2-4\text{x}+4}{2\left(x-2\right)\left(x+2\right)}\)

= \(\frac{\left(x-2\right)^2}{2\left(x-2\right)\left(x+2\right)}\)

= \(\frac{x-2}{2\left(x+2\right)}\)

\(\frac{x+2}{x}+\frac{2x-1}{2-x}-\frac{x-8}{x^2-2x}\)

\(=\frac{x+2}{x}-\frac{2x-1}{x-2}-\frac{x-8}{x\left(x-2\right)}\)

\(=\frac{\left(x-2\right)^2}{x\left(x-2\right)}-\frac{x\left(2x-1\right)}{x\left(x-2\right)}-\frac{x-8}{x\left(x-2\right)}\)

\(=\frac{x^2-4x+4-2x^2+x-x+8}{x\left(x-2\right)}=\frac{-x^2-4x+12}{x\left(x-2\right)}\)

\(=\frac{\left(x+6\right)\left(x-2\right)}{x\left(x-2\right)}=\frac{x+6}{x}\)

Bài làm 

\(\frac{xy}{x^2-y^2}+\frac{x^2+2x}{x^2-y^2}=\frac{xy+x^2+2x}{x^2-y^2}=\frac{x\left(x+2+y\right)}{\left(x-y\right)\left(x+y\right)}\)

Học tốt 

\(x^3-2x^2-x+2=0\Leftrightarrow x^3-x-2x^2+2=0\)

\(\Leftrightarrow x\left(x^2-1\right)-2\left(x^2-1\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x^2-1\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x-1\right)\left(x+1\right)=0\Leftrightarrow x=2;\pm1\)

\(x^3-2x^2-x+2=0\)

\(x^2.\left(x-2\right)-\left(x-2\right)=0\)

\(\left(x-2\right)\left(x^2-1\right)=0\)

\(\left(x-2\right)\left(x-1\right)\left(x+1\right)=0\)

\(\Leftrightarrow\hept{\begin{cases}x-2=0\\x-1=0\\x+1=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=2\\x=1\\x=-1\end{cases}}}\)

Vậy \(x=2;x=1;x=-1\)

\(x^2+6x=0\)

\(x.\left(x+6\right)=0\)

\(\Leftrightarrow\hept{\begin{cases}x=0\\x+6=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=0\\x=-6\end{cases}}}\)

Vậy \(x=0;x=-6\)

\(\left(x-4\right)\left(x+4\right)-x\left(x-2\right)=0\)

\(x^2-16-x^2+2x=0\)

\(2x-16=0\)

\(2.\left(x-8\right)=0\)

\(x-8=0\)

\(x=8\)

Vậy \(x=8\)

\(x^2+6x=0\Leftrightarrow x\left(x+6\right)=0\Leftrightarrow x=0;-6\)

\(\left(x-4\right)\left(x+4\right)-x\left(x-2\right)=0\)

\(\Leftrightarrow x^2-16-x^2+2x=0\Leftrightarrow-16+2x=0\Leftrightarrow x=8\)