[tex]a\cdot 3=27 \\ \Rightarrow a=\frac{27}{3}=\boxed{9}; \\\\ 4\cdot a=36 \\ \Rightarrow a=\frac{36}{4}=\boxed{9}; \\\\\ a:3=7 \\ \Rightarrowa=7\cdot3=\boxed{21}; \\\\ a:4=7 \\ \Rightarrow a=7\cdot4=\boxed{28}; \\ \\ 32:a=4 \\ \Rightarrow a=\frac{32}{4}=\boxed{8}; \\ \\ 12:a=3 \\ \Rightarrow a=\frac{12}{3}=\boxed{4}.[/tex]
