$x^2-x+6=0$

$\left(x^6+4\right)\left(x^6-8\right)$

$5-\left(-67\right)-87-+\left(-72\right)$

$\lim_{x\to\frac{\pi}{2}}\left(-\frac{1-sen\left(x\right)}{cos\left(x\right)}\right)$

$\left(x^{-\frac{2}{3}}\right)^6$

$\lim_{x\to-1}\left(\frac{2x^2+x}{x+1}\right)$

$\frac{1}{8}\cdot0.5$