simplify this expression (3xy)^2(2x^2z)^3

(3xy)^2 = 3^2 x^2 y^2 = 9 x^2 y^2

(2x^2z)^3 = 2^3 (x^2)^3 z^3 = 8 x^6 z^3
multiplying all that, we get

72 x^8 y^2 z^3