a) 9 . 12 = 4 . 27
\(\Rightarrow\text{ }\frac{9}{4}=\frac{27}{12}\); \(\frac{9}{27}=\frac{4}{12}\); \(\frac{12}{4}=\frac{27}{9}\); \(\frac{12}{27}=\frac{4}{9}\)
b) 4,8,16,32
\(\Rightarrow\text{ }\text{ }4.32=8.16\)
\(\Rightarrow\text{ }\frac{4}{8}=\frac{16}{32}\); \(\frac{4}{16}=\frac{8}{32}\); \(\frac{32}{8}=\frac{16}{4}\); \(\frac{32}{16}=\frac{8}{4}\)