Question

Aflati ultima cifra a numerelor a = 5^31 + 7^31; b = 8^102 – 6^25 – 7^32

Answer 1

a=5^31 + 7^ 31

u(5^31)=5

u(7^31)=u(7^4×7+3)=u(7^3)=3

u(a)=5+3=8

b=8^102 - 6^25- 7^32

u(8^102)=u(8^4×25+2)=u(8^2)=4

u(6^25)=6

u(7^32)=u(7^4×8+0)=u(7^0)=1

u(b) =4+6+1=1

Sper ca te-am ajutat!