Cộng, trừ các phân thức sau: 3/2x^2 +2x + 2x-1/x^2 -1 -2/x

* Hướng dẫn giải

$\begin{array}{l}\frac{3}{2{\mathrm{x}}^2+2\mathrm{x}}+\frac{2\mathrm{x}-1}{{\mathrm{x}}^2-1}-\frac{2}{\mathrm{x}}\\ =\frac{3}{2\mathrm{x}\left(\mathrm{x}+1\right)}+\frac{2\mathrm{x}-1}{\left(\mathrm{x}-1\right)\left(\mathrm{x}+1\right)}-\frac{2}{\mathrm{x}}\\ =\frac{3\mathrm{x}-3+4{\mathrm{x}}^2-2\mathrm{x}-4{\mathrm{x}}^2+4}{2\mathrm{x}\left(\mathrm{x}-1\right)\left(\mathrm{x}+1\right)}=\frac{\mathrm{x}+1}{2\mathrm{x}\left(\mathrm{x}-1\right)\left(\mathrm{x}+1\right)}=\frac{2}{2\mathrm{x}\left(\mathrm{x}-1\right)}\end{array}$