$\frac{d}{dx}\left(xy\:sqrt\:\left(1+y^2\right)=0\right)$

$\lim_{x\to0}\frac{7x^4-4x^3+8x}{x}$

$2+x+2$

$\left(2+\left(-1\right)\right)+3\left(3-5\right)$

$\int\frac{e^{-\cot\left(z\right)}}{\sin^2\left(z\right)}dz$

$\frac{d}{dx}y^2=\frac{x^2}{xy-4}$

$\frac{6x-18}{x^2-3x}$