$\frac{x-x^2+5x^3-4x^2}{-x^2-1}$

$2x^2-4x-6x^2$

$\frac{2\tan\left(x\right)}{1+\tan^2\left(x\right)}\cdot\cot\left(2x\right)$

$\int\frac{7x-30}{x^2-9x+20}dx$

$-2n^5+n^3-2n^2+8-\left(-5n^5+3n^4+6n^3-7\right)$

$\lim\:_{x\to\:-\infty}\left(\frac{ln\left(x^4+5\right)}{11x+2}\right)$

$\frac{d}{dx}\left(3x^2y^2=2x+y\right)$