$\frac{dy}{dx}=1200y-y^2$

$306=\left(9-2x\right)\left(30-2x\right)+2\left(30-2x\right)\left(x\right)+2\left(9-2x\right)\left(x\right)$

$\left(4-3y^3\right)^2$

$\frac{dx}{dy}4\left(x^2+1\right)x\left(\frac{\pi}{4}\right)=1$

$56m^2+40mn+16n^2$

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

$18x^2-45x+27$