$\left(7x^3\:y^2+\:8xy\right)\left(7x^3\:y^2-\:8xy\right)$

$3x+2y-y+2y+x^2-2x^2-6x$

$3x^2-6x-10$

$sen\left(y-\frac{\pi\:}{4}\right)$

$\frac{\left(1+cos\left(z\right)\left(1-cos\left(z\right)\right)\right)}{tan^2\left(z\right)}=cos^2$

$\frac{d^4}{dx^4}\left(2y^{-1}+3y^4\right)$

$-n+\left[-4\right]-\left[-4n\right]+6$