$\frac{dy}{dx}\left(y^3+y^2-5y-x^2+4=0\right)$

$2-44$

$\left(2x+y\right)dx+\left(-x-6y\right)dy=0$

$\lim_{x\to+\infty}\left(x\log\left(\left(1+\frac{1}{x}\right)^x\right)-x\log\left(1+\frac{1}{x}\right)^{x+1}\right)$

$\frac{3x^2-\left(7x+1\right)\sqrt{x}+5}{x-1}$

$\lim_{x\to-4}\left(\frac{x^2-x-20}{x+4}\right)$

$\lim\:_{h\to\:0}\:\:\frac{x^2\:+\:3xh^2+h^3}{2xh+5h^2}$