\[a^{14}\ :\ *\ \cdot a^{9} = a^{11}\]
\[a^{14}\ :\ *\ = a^{11}\ :a^{9}\]
\[a^{14}\ :\ *\ = a^{2}\]
\[*\ = a^{14}\ :a^{2}\]
\[*\ = a^{12}.\]