$\lim_{x\to0}\left(1+\frac{2}{x}\right)\cdot\frac{x}{2}$

$\frac{6u^5+9u^3-1}{3u^2}$

$\frac{12x^3-11x^2+10x-4}{x-11}$

$1-\left[6-\left(46-4\right)-50+\left(42-16\right)\right]-3$

$sen^3\left(x\right)csc^4\left(x\right)$

$-\frac{1}{3}.3\:mn\:.3\:m\:^2$

$\sin\left(8\right)=\sin\left(4\right)\cos\left(4\right)$