What is the simplest form of 4th root of 81 x to the 8th power y to the 5th power ?

Rewrite the expression inside the fourth root as 3⁴ · (x²)⁴ · y⁴ · y. Taking the fourth root of each perfect fourth power gives 3x²y, with √[4]{y} remaining. So the simplest form is 3x²y√[4]{y}, which is choice B.

AI-written and checked against the verified answer.