Vamos resolver !
[tex3]\frac{\sqrt{12^{2}+5^{2}}}{26}+\sqrt[3]{-8}+\sqrt{(-1)^{2}}[/tex3]
[tex3]\frac{\sqrt{144+25}}{26}+(-2)+\sqrt{1}[/tex3]
[tex3]\frac{\sqrt{169}}{26}-2+1[/tex3]
[tex3]\frac{13}{26}-1[/tex3]
[tex3]\frac{1}{2}-1[/tex3]
[tex3]\frac{1}{2}-\frac{2}{2}=\boxed{\boxed{-\frac{1}{2}}}[/tex3]