$\frac{d}{dx}xy+x-2y-1=0$

$-8\left(5x+8y-8\right)$

$x^3yz^2+xyz^3+x^2z^3+x^3y^2z^2$

$\cos\left(4x\right)-4\cos\left(2x\right)+3=8\sin^4\left(x\right)$

$\lim_{x\to0}\left(\frac{\pi\cos\left(\pi x\right)}{x^2-2x+1}\right)$

$6x\left(7x+6\right)$

$\frac{dy}{dx}\left(4\cos\left(x\right)\sin\left(y\right)=1\right)$