Răspuns:
a)
[tex]( \sqrt{5} )^{ - 4} \times ( \sqrt{5})^{8} = [/tex]
[tex] = 5^{ - 2} \times \sqrt{5^{8} } = [/tex]
[tex] = 5^{ - 2} \times 5 ^{4} = [/tex]
[tex] = 5^{2} = [/tex]
[tex] = 25[/tex]
b)
[tex]( \sqrt{2} )^{15} \div ( \sqrt{2} )^{19} = [/tex]
[tex] = \sqrt{2}^{ - 4} = [/tex]
[tex] = {2}^{ - 2} = [/tex]
[tex] = \frac{1}{ {2}^{2} } = [/tex]
[tex] = \frac{1}{4} [/tex]
