$81^{4^4}$

$\frac{x^2+3x-1}{x+1}$

$x\frac{dy}{dx}=2+x-2y-xy$

$\lim_{x\to0}\left(x^{-\frac{18}{ln\left(x\right)}}\right)$

$\lim_{x\to0}\left(\frac{\sin\left(x\right)}{x}\right)^{\frac{1}{x}}$

$\frac{\left(\frac{1g^2k^3}{6}\right)}{\left(-\frac{1g^4k^4p^3}{8}\right)}$

$3sec^2\:\left(3z+2\right)$