$\lim_{x\to\infty}\left(\sqrt{3x^2+6x+2}-\sqrt{3x^2+5x}\right)$

$2x.\left(-3n^3\right)$

$\int_{-\infty\:}^0\left(\frac{x}{x^2+4}\right)dx$

$\frac{-18x^4y^7z^3}{6xy^2z^2}$

$\frac{x^3+8x^2-5x+9}{x^2-2}$

$\frac{52}{239}\sqrt{x^{13}}+c$

$\frac{a}{2u^{3}+6u}+\frac{2}{u^{2}+3}-\frac{3}{20}$