$\frac{cos\left(x\right)}{1+sin\left(x\right)}=sec\left(x\right)-tan\left(x\right)$

$9x^2+30x+100$

$cosx\:=\:\frac{1}{cosx}\:-\:sinxtanx$

$3x^3y^2\left(4x^3-5xy\right)-4y^2\left(x^6-3x^4y\right)$

$\sqrt[27]{\sqrt[4]{\left(-2\right)}}$

$\lim_{x\to2}\left(x-\sqrt{\frac{6-x}{x-2}}\right)$

$18\::\:-9$