Given the expression :
[tex](-xy^3z)\cdot(-x^3y^4z^3)^3[/tex]We will use the following rules :
[tex]\begin{gathered} a^m\cdot a^n=a^{m+n} \\ \\ (a^{m)n}=a^{m\cdot n} \end{gathered}[/tex]so, the answer will be as following :
[tex]\begin{gathered} (-xy^3z)\cdot(-x^3y^4z^3)^3 \\ \\ =(-xy^3z)\cdot(-x^9y^{12}z^9) \\ \\ =x^{10}y^{15}z^{10}^{} \end{gathered}[/tex]