$\frac{dy}{dx}+2y=x\:,\:y\left(0\right)=0$

$\frac{a^3-3a^2-a+3}{a-2}$

$\lim_{x\to1}\left(\frac{\arctan\left(x\right)}{\arccos\left(x\right)}\right)$

$\lim_{x\to\infty}\left(\sqrt{x^2+4x+9}-x\:\right)$

$\frac{dy}{dx}=\frac{\left(-4x+2y\right)}{\left(-2x+5y\right)}$

$\:x^3+6x^2+12x$

$\left(3x^2-y\right)^4$