[tex]a) \ 3^{7}\times3^{-4} = 3^{7+(-4)} = 3^{7-4} = 3^{3} = 27\\\\b) \ 7^{-4}:7^{-6} = 7^{-4-(-6)} = 7^{-4+6} =7^{2} = 49\\\\c) \ (2^{2})^{-3} = 2^{2\cdot(-3)} = 2^{-6} = (\frac{1}{2})^{6} = \frac{1}{64}[/tex]
Wyjaśnienie:
[tex]a^{m}\times a^{n} = a^{m+n}\\\\a^{m}:a^{n} = a^{m-n}\\\\(a^{m})^{n} = a^{m\cdot n}\\\\a^{-n} = (\frac{1}{a})^{n}, \ \ \ a\neq 0[/tex]
