[tex]a)\\\\2^{9} \cdot (\dfrac{1}{4} )^{9} \div (\dfrac{1}{2} )^{5}=(2\cdot \dfrac{1}{4} )^{9} \div (\dfrac{1}{2} )^{5}= ( \dfrac{1}{2} )^{9} \div (\dfrac{1}{2} )^{5}=(\dfrac{1}{2} )^{9-5} =(\dfrac{1}{2} )^{4}=\dfrac{1}{16} \\\\b)\\\\\dfrac{(\dfrac{1}{5} )^{8}\div (\dfrac{2}{25} )^{8} }{2,5^{6} } =\dfrac{(\dfrac{1}{5} \div \dfrac{2}{25} )^{8}}{(2\dfrac{1}{2} )^{6}} =\dfrac{(\dfrac{1}{5} \cdot \dfrac{25}{2} )^{8}}{(\dfrac{5}{2} )^{6}} =[/tex]
[tex]=\dfrac{( \dfrac{5}{2} )^{8}}{(\dfrac{5}{2} )^{6}}=( \dfrac{5}{2} )^{8-6}=( \dfrac{5}{2} )^{2}=\dfrac{25}{4} =6\dfrac{1}{4}[/tex]
korzystam ze wzorów:
[tex]x^{n} \cdot y^{n} =(x\cdot y)^{n} \\\\x^{n} \cdot x^{m} =(x)^{n+m} \\\\x^{n} \div x^{m} =(x)^{n-m} \\\\x^{n} \div y^{n} =(x\div y)^{n}[/tex]