$xy\:+\:6y\:=\:3xy$

$\frac{tan^2\left(x\right)+2\tan\left(x\right)+1}{\tan^2\left(x\right)-1}$

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

$\int_0^{\frac{\pi}{4}}\left(\tan^5\left(x\right)\sec^2\left(x\right)\right)dx$

$x+2+x-6-x-4x$

$\frac{4-x^2}{3x-2}-2\left(x-1\right)$

$\frac{2\sqrt{a}+2a}{1+a}$