$-189\:_{\:-21}$

$\frac{2}{3}and\:\frac{4}{9}$

$y=\frac{1}{6-2x}$

$\lim_{x\to\infty}\left(\frac{x^3-2x^2+7x-21}{x^6+1}\right)$

$\lim_{n\to0}\left(\frac{\frac{n^3}{30}-60n}{2000n^2}\right)$

$\int - 2 x ^ { 2 } e ^ { x } d x$

$\left(6f^2-d^2h^3\right)\left(6f^2-5\right)$