$\int x\left(1-2x\right)dx$

$\int4x^3\sqrt{x^4+2}dx$

$\frac{dy}{dx}=\frac{x\sqrt{4-y^2}}{\sqrt{1+x^2}}$

$\left(x-ch+2l\right)\frac{z}{1}+x$

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

$\frac{xy+3x-4y-12}{2xy+4x-8y-16}$