$18x^5+3x^4$

$2x^2-5x-12$

$2\sin\left(2x\right)\cdot\cos\left(y\right)$

$\:\:\left(-x\:\right)\:^{\:-2\:\:}\:\:\:\:\left(-x\:\right)\:^{\:-3\:\:}\:\:\:$

$\frac{d}{dx}\left(\frac{\left(y+6\right)}{\left(6y^2+x\right)}\right)$

$\lim_{x\to\frac{3}{2}}\left(\frac{\sqrt{8x^3-27}}{4x^2-9}\right)$

$2\sqrt{5}+\sqrt{5}-4\sqrt{5}$