$400^{10}+40^5+1$

$\:\int\:\left(\frac{3x^2-51}{\sqrt{x^3-51x+23}}\right)\:dx$

$\lim_{x\to0}\left(\frac{x^7-2x^3}{x^2}\right)$

$xy+3y-2x+5y-3xy$

$t^{4}-9x^{2}$

$\int\frac{4x^3-3x^2-3}{\left(x^2+3\right)\left(x+1\right)\left(x-2\right)}dx$

$\left(2x+e^y\right)dx\:+\:xe^y\:dy=0$