a) U (2^100)=U(2^4k)=U(2^4)=U(16)=6
b) U(3^2000)=U(3^4k)=U(3^4)=U(81)=1
c) U(4^(2k+1))=U(4^1)=4
d) U (5^35)=5
e) U(6^1000)=6
f) U(2^(4k+2))=U(2^2)=4
g) U(7^(4k+1))=U(7^1)=7
h)U(8^(4k+3))=U(8^3)=2
i) U(9^(2k+1))=9
j) U(3*2^(4k+3)+U(5*7^4k)=U(3*8+5*1)=U(24+5)=9
k) U(4*3^(4k+1)+2*5)=U(4*3)=2
