$\left(3m^2+7n^3\right)\left(9m^4-21m^2n^3+49n^6\right)$

$11b+6\ge14b+3$

$\cos+\cos^3$

$\left(x-y\right)\left(x^2-y^2\right),para\:x=2,y=3$

$\left(8x+2x^2\right)^2$

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

$\frac{d}{dx}\left(cos\left(xy\right)=xe^y\right)$