[tex]\displaystyle\bf\\1)\\\\\frac{8tg22,5^\circ}{2-2tg^{2} 22,5^\circ} =\frac{8tg22,5^\circ}{2\cdot(1-tg^{2} 22,5^\circ)} =\\\\\\=2\cdot\frac{2tg22,5^\circ}{1-tg^{2} 22,5^\circ} =2\cdot tg(2\cdot 22,5^\circ)=2tg45^\circ=2\cdot 1=2\\\\2)\\\\\frac{3Ctg^{2} 15^\circ-3}{6Ctg15^\circ} =\frac{3\cdot(Ctg^{2} 15^\circ-1)}{3\cdot 2Ctg15^\circ} =Ctg(2\cdot 15^\circ)=\\\\\\=Ctg30^\circ=\sqrt{3}[/tex]