$\lim_{x\to0}\left(\frac{ln\left(x+1\right)}{cosx+e^x-1}\right)$

$\log_{10}\left(x-1\right)-\log_{10}\left(x+1\right)$

$\frac{du}{dt}=e^{2u+5t},\:u\left(0\right)=15$

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

$-110\left(-25\right)$

$\frac{-81}{+27}-18+3$

$\int_{\frac{\sqrt{2}}{2}}^1\left(\frac{1}{\arctan\left(x\right)\left(1+x^2\right)}\right)dx$