| \frac{1}{x^4+x^3+2x^2+x+1}-\frac{2}{x^4+x^2+1}=\frac{-1}{(x^2-x+1)(x^2+1)} | \frac{1}{x^4+x^3+x^2+x+1}+\frac{x^4+x^3+x^2+2}{x^5-1}=\frac{1}{x-1} |
| \frac{1}{x^2+x+1}+\frac{x^2+2}{x^3-1}=\frac{1}{x-1} | \frac{2x+4}{x^2-1}+\frac{x+2}{x^2-3x+2}=\frac{3x+6}{x^2-x-2} |
| \frac{-2}{x}+\frac{x-6}{x^2-3x}-\frac{x}{x^2-9x+18}=\frac{-2}{x-6} | \frac{4}{x}+\frac{x+12}{x^2-3x}+\frac{x}{x^2+9x-36}=\frac{6x+60}{x^2+9x-36} |
| \frac{2}{x}+\frac{x+10}{x^2-5x}-\frac{9x}{x^2+5x-50}=\frac{-6}{x+10} | \frac{-5}{x}+\frac{x-20}{x^2-4x}+\frac{x}{x^2-24x+80}=\frac{-3x+80}{x^2-24x+80} |
| \frac{1}{x^4+x^2+1}+\frac{x^4+2}{x^6-1}=\frac{1}{x^2-1} | \frac{1}{4x^4+2x^2+1}+\frac{4x^4+2}{8x^6-1}=\frac{1}{2x^2-1} |
| \frac{3}{x}+\frac{x+3}{x^2-x}-\frac{16x}{x^2+2x-3}=\frac{-12}{x+3} | \frac{-3}{x}+\frac{x-15}{x^2-5x}+\frac{x}{x^2-20x+75}=\frac{-x+30}{x^2-20x+75} |