$\lim_{x\to-\infty}\frac{x\left(1-\sqrt{x^2-1}\right)-x^2}{x-2}$

$\frac{dy}{dx}+\frac{2y}{20-x}=4,\:y\left(0\right)=10$

$\left(2\right)\frac{3}{4}n\:\left(1\right)$

$\int\left(\frac{\sin\left(2\cdot x\right)}{4\cdot\sin\left(x\right)^2+5\cdot\cos\left(x\right)^2}\right)dx$

$\frac{d}{dx}186.5$

$cos3x-cosx$

$56m^5n^4p^4+48m^4np-24m^2np^4$