I'm not sure with this but:
= 81z^3 / 36y ÷ 27(2z^2) / 12xy (rewrite)
= 81z^3 / 36y ÷ 54z^2 / 12xy (multiply the 27 to the 2z^2)
= 81z^3 / 36y * 12xy / 54z^2 (change sign from ÷ to *; reciprocate)
= 3z / 3y * x / 2 (simplify the equation)
= 3xz / 6 OR xz/2 (1/2*xz) multiply numerator and denominator ; simplify
*if the answer is wrong, I'm kinda sure the solution is like that.