$\lim_{x\to\infty}\left(\frac{3x^2}{x-1}\right)-\left(\frac{3x^2}{x+1}\right)$

$f\left(x\right)=\left(x+1\right)^2-2x$

$\frac{32n^2-54m^2+12mn}{8m\:-9m}$

$10c^3-80c-5c^6+5c^7$

$6x^2+43x-40$

$ln\left|e^0-1\right|$

$\frac{3}{5}m^{2}-2mn+\frac{1}{10}n^{2}-\frac{1}{3}mn+2mn-2n^{2}$