$\frac{dy}{dx}=\frac{\left(x+3\right)}{\left(y-3\right)}$

$\lim_{x\to4}\left(\frac{\sqrt{x}-x^2}{\ln\left(x\right)}\right)$

$\frac{cosx}{-senx}=\frac{1}{cosx}+\frac{1}{cot}$

$\lim_{q\to3}\left(\frac{3q^2-12q+14}{2q-6}\right)$

$25m^4-25$

$m+2\le5$

$\lim_{x\to0}\left(\frac{8x^2}{1}\right)$