5.
[tex]I. \ \ 2^{15}:2^{12} = 2^{15-12} = 2^{3} = 8\\\\II. \ \ 8^{3}:2^{4} = (2^{3})^{3}:2^{4} = 2^{3\cdot3}:2^{4} = 2^{9}:2^{4} = 2^{9-4} = 2^{5} = 32\\\\III. \ \ 2^{20}\cdot0,5^{20} = (2\cdot0,5)^{20} = 1^{20} = 1\\\\IV. \ \ 3^{4}:3^{2} = 3^{4-2} = 3^{2} = 9\\\\Odp. \ B. \ II.[/tex]
