\[\left( \frac{1}{3}\text{cd} \right)^{2} = \left( \frac{1}{3} \right)^{2}\left( \text{cd} \right)^{2} =\]
\[= \frac{1}{9}c^{2}d^{2} \Longrightarrow коэффициент\ \frac{1}{9};\ \ \]
\[степень\ \ 4.\]