$\int\frac{\sqrt{x^{2}-36}}{x^{3}}dx$

$\left(n^6-25m^4\right)=\left(n^3+5m^2\right)\left(n^3-5m^2\right)$

$12x^2-\:12x\:+\frac{72}{t}$

$\lim_{x\to1}\left(\frac{3x-3}{4+10^x}\right)$

$\frac{2\:x^2-8}{x^2+4x+4}$

$2x^2-x-1-\left(4x-6\right)$

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