$\lim_{x\to0}\left(\frac{1-\cos\left(x\right)}{tg\left(x\right)}\right)$

$\left(x-3y\right)\left(x+3y\right)\left(x^2+9y^2\right)$

$\lim_{x\to-3}\left(\frac{3x^2-15}{x-\sqrt{5}}\right)$

$\left(5a-8bc\right)\left(9a-10bc\right)$

$4598.56\cdot7$

$16m^2-8m=1$

$\int2\left(4^{6-5x}\right)dx$