Răspuns :
u(16 ^2019)=6
u(17^2019)=7
u(18^2020)=8
u(19^2019)=9
u(20^2020)=0
deci ultima cifra a sumei tale este 6+7+8+9+0=0
u(17^2019)=7
u(18^2020)=8
u(19^2019)=9
u(20^2020)=0
deci ultima cifra a sumei tale este 6+7+8+9+0=0
U(16^2019)=6
U(17^2019)=7
U(18^2020)=8
U(19^2019)=9
U(20^2020)=0
6+7+8+9+0=30 deci ultima cifra e 0
U(17^2019)=7
U(18^2020)=8
U(19^2019)=9
U(20^2020)=0
6+7+8+9+0=30 deci ultima cifra e 0