Răspuns :
[tex]a=3^{20} = 3^{2 \times 10} = (3^2)^{10}=9^{10} \\ \\ b=2^{30} = 2^{3 \times 10} = (2^3)^{10}=8^{10} \\ \\ 9^{10} \ \textgreater \ 8^{10}~~~ \Longrightarrow ~~~3^{20}\ \textgreater \ 2^{30}~~~ \Longrightarrow ~~~a \ \textgreater \ b[/tex]