$\left(r-t+n\right)^2$

$2cos\left(2x\right)-1\ne\:0$

$-1=\frac{-x-2}{x^2-5x}$

$\int\left(\frac{a}{x^2}\right)dx$

$\frac{d}{dx}\left(x^3y+x^2=y^2\right)$

$\sin\left(2\pi\left(770\right)\tan\left(x\right)\right)+\sin\left(2\pi\left(1209\right)\tan\left(x\right)\right)$

$\left(8x\:-\:2y\right)\left(8x\:+\:2y\right)\:$