$-\left(4t+5.7u-1.2\right)$

$\frac{\sin\:\left(\theta\:\right)}{1-\cos\:\left(\theta\:\right)}=\frac{1+\cos\:\left(\theta\:\right)}{\sin\:\left(\theta\:\right)}$

$\frac{a}{\:x}+\frac{bx+c}{x^2+1}$

$5x^4-6x^3-4x^4-3x^3$

$\int\frac{x^2+3}{x^4+2x^2+1}dx$

$\frac{x^2-9}{9}$

$\lim\:_{x\to\:-\infty\:}\left(\frac{\:x^2+5}{x^3\:}\right)$