$\frac{12x^6-18x^4+6x^2}{12x^2}$

$x^2y^4+2xy^2z+z^2$

$\left(\left(7x-5\right)\left(x^2+1\right)\right)$

$y^2-7y+15$

$\tan\left(x\right)^2\left(\tan\left(x\right)^4+3\tan\left(x\right)^2+3\right)+1$

$2\cos\left(x\right)+2\sin\left(x\right)=\sqrt{6}$

$\frac{d^2}{dy^2}\left(x^2\cdot e^{3xy}+4xz^3\right)$