$x^2-5<x$

$5\left(x+10\right)-25=5x+25$

$\frac{1}{\tan\left(x+y\right)}-\frac{1}{\tan\left(x\right)}$

$20.x^3-15.x^2+5.x$

$\frac{d}{dy}\left(\ln\left(\frac{\left(1+y\right)\left(1+x\right)}{\left(1-y\right)\left(1-x\right)}\right)\right)$

$\frac{sin150\:+\:sin120}{cos210\:-\:cos300}$

$f\left(x\right)=2x\ln\left(6x\right)-2x$