25)200:5=40 26)u(5^2018) 5^1=5 5^2=25 5^3=...5 . . . 5^8=..5 2018:1=2018 u(5^2018)=u(5^2018(tot la putere)•1)=1 U(1^2018) 1^1 . . . 1^8=1 2018:1=2018 U(1^2018)=u(1^2018(tot la putere)•1=1 Asa faci si cu celelalte si la sfarsit ....1+...1+....1-...1=...2