\[- 5x^{3}y^{5} \cdot \left( - \frac{1}{5}x^{5}y^{3} \right) =\]
\[= x^{3 + 5}y^{5 + 3} = x^{8}y^{8} =\]
\[= \left( x^{4}y^{4} \right)^{2} \Longrightarrow да.\]