The correct answer is 216x⁶y⁵.
Explanation:
The first thing we do is raise the last monomial to the third power.
(4xy)(2x²y)(3xy)³
=(4xy)(2x²y)(3³x³y³)
=4xy(2x²y)(27x³y³).
Now we can multiply the first two monomials. When we multiply powers with the same base, we add the exponents:
8x³y²(27x³y³).
We multiply these last two monomials, again adding the exponents:
216x⁶y⁵.