$c=\frac{sen32^{\circ}\cdot\:sec58^{\circ}}{tag20^{\circ}}\cdot\:ctg70^{\circ}+sen54^{\circ}\cdot\:sec36^{\circ}$

$18+12:\left(-\left(-8\right)+3x\left(-2\right)\right)$

$3x^2+13x+14=0$

$\left[\frac{\left(n+2\right)}{e^n+1}x^n\right]$

$log3x$

$\frac{9}{x^2+5}\:=\:\frac{5}{x^2+1}$

$\lim_{x\to0}\left(\frac{x+2}{7x+11}\right)^{2x}$