a) $(\frac{-1}{3})^{4}=\frac{1}{81};(\frac{-2}{3})^{3}=\frac{-8}{27};(2\frac{1}{2})^{3}=(\frac{5}{2})^{3}=\frac{125}{8};(-0.2)^{3}=-\frac{1}{125};(-125.9)^{0}=1;(0.3)^{4}=\frac{81}{10000}$
b) $(\frac{-1}{2})^{2}=\frac{1}{4};(\frac{-1}{2})^{3}=\frac{-1}{8};(\frac{-1}{2})^{4}=\frac{1}{16};(\frac{-1}{2})^{5}=\frac{-1}{32}$