$\frac{\left(81^{-1}x^4y^{-3}\right)^{-1}}{\left(27^{-1}x^{-2}y^4\right)^{-2}}$

$\int_0^63\sqrt{36-x^2}dx$

$\int-50\:dx$

$15 > \frac { 3 x + 1 } { 2 }$

$\left(4a^2b+3c\right)\left(4a^2b-3c\right)$

$\frac{dy}{dx}=-7xe^y$

$\lim_{x\to\infty}\left(\frac{x\cdot sin\left(\frac{1}{x}\right)}{cos\left(\frac{1}{x}\right)}\right)$