$\frac{1.6137}{2}$

$\frac{1}{cos^2}-tana$

$\ln\left(x\right)+\ln\left(x-5\right)=\ln\left(6x\right)$

$\lim_{x\to1}\left(\frac{\left(x-1\right)^2}{-\left(\ln\left(x\right)\cdot x\right)}\right)$

$\log_{10}\left(2ax-4a\right)-\:\log_{10}\left(2ax\right)$

$\frac{4+x}{16+8x+x^2}$

$\lim_{x,y\to0,0}\left(\frac{x^2\cdot y^3}{x^5+y^5}\right)$