$\frac{2x^3+6x^2-x-3}{x^3+3x^2+x-3}$

$\lim_{x\to\infty}\left(\frac{\ln\left(x^2+3x+4\right)-\ln\left(x^2-2x+5\right)}{x^2}\right)$

$\frac{2x^3+4y^3}{xy}$

$3^{-4}\cdot3^{-1}\cdot3^6$

$\left(2x^4z^2\right)x\:\left(5z^5\right)$

$\frac{dy}{dx}+y-e^x=0$

$\left(1.98\right)^{12}$