You have to break up 384 into numbers that can be taken out to the radical.
You can break up 384 into 2^3*2^3*6.
Since two 2’s can be taken you would have 4 on the outside and a 6 and x^4 left on the inside.
x^3 can be taken out, leaving an x inside the radical.
The final answer would be 4x on the outside and 6x left under the cubed radical