[m]y`=\frac{(x+2)`\cdot lnx-(x+2)\cdot (lnx)`}{ln^2x}[/m]
[m]y`=\frac{ lnx-(x+2)\cdot \frac{1}{x}}{ln^2x}[/m]
[m]y`=\frac{x\cdot lnx-x-2}{x\cdot ln^2x}[/m]
[m]y=x+\frac{2}{lnx}[/m]
[m]y`=1-\frac{2}{ln^2x}\cdot (lnx)`[/m]
[m]y`=1-\frac{2}{ln^2x}\cdot\frac{1}{x}[/m]
[m]y`=1-\frac{2}{x\cdot ln^2x}[/m]