164

a)
4^{1{,}5}=4^{\frac{3}{2}}=\sqrt{4^3}=\sqrt{4^2}\sqrt{4}=4\sqrt{4}
b)
4^{0{,}75}=4^{\frac{3}{4}}=\sqrt[4]{4^3}=\sqrt[4]{2^6}=\sqrt[4]{2^4}\sqrt[4]{2^2}=2\sqrt[4]{4}
c)
 
27^{\frac{2}{3}}=\sqrt[3]{27^2}=\sqrt[3]{3^6}=3^{\frac{6}{3}}=3^2=9
d)
25^{-\frac{3}{2}}=\frac{1}{\sqrt{25^3}}=\frac{1}{\sqrt{5^6}}=5^{-\frac{6}{2}}=5^{-3}=\frac{1}{125}