4) a) [tex]\displaystyle\frac1{256}=\frac{1}{2^8}=\left(\frac{1}{2}\right)^8[/tex]
b) [tex]\displaystyle\frac{16}{81}=\frac{2^4}{3^4}=\left(\frac{2}{3}\right)^4[/tex]
5) a) [tex]\displaystyle\frac1{64}=\frac{1}{2^6}=\left(\frac{1}{2}\right)^6[/tex]
b) [tex]\displaystyle\frac{32}{243}=\frac{2^5}{3^5}=\left(\frac23\right)^5[/tex]
