Thực hiện nhân, chia các phép tính: (1/x^2 + x - 2-x/ x+1) ; (1/x +x -2)

* Hướng dẫn giải

$\begin{array}{l}\left(\frac{1}{{\mathrm{x}}^2+\mathrm{x}}-\frac{2-\mathrm{x}}{\mathrm{x}+1}\right):\left(\frac{1}{\mathrm{x}}+\mathrm{x}-2\right)\\ =\left[\frac{1+{\mathrm{x}}^2-2\mathrm{x}}{\mathrm{x}\left(\mathrm{x}+1\right)}\right]:\frac{{\mathrm{x}}^2-2\mathrm{x}+1}{\mathrm{x}}=\frac{{\mathrm{x}}^2-2\mathrm{x}+1}{\mathrm{x}\left(\mathrm{x}+1\right)}.\frac{\mathrm{x}}{{\mathrm{x}}^2-2\mathrm{x}+1}=\frac{1}{\mathrm{x}+1}\end{array}$