Answer:
[tex]\large\boxed{\left(3x^2y\right)^3=27x^6y^3}[/tex]
Step-by-step explanation:
[tex]\text{Use}\ (ab)^n=a^nb^n\ \text{and}\ (a^n)^m=a^{nm}\\\\\left(3x^2y\right)^3=3^3(x^2)^3y^3=27x^6y^3[/tex]