$\frac{dy}{dx}=\frac{y^2}{\left(1+y^2\right)\left(x^2+1\right)}$

$x2-3x^3$

$\frac{\sin\left(x\right)}{\cos\left(x\right)}\sin\left(x\right)\cos\left(x\right)$

$\left(2k+3e\right)\left(2k-3e\right)$

$x^2-17x+70$

$\frac{dy}{dx}=\frac{y\left(1+x\right)}{x}$

$\frac{1}{27}+\frac{x^6}{216}$