Simplify and combine like radicals:?

Question

9^4√256x + 9^4√81x

Assume that x represents a positive number.

I came up with the answer of 27^4√x

Answer 1

I got 9^4*2^5 square roots of x

The process...

The square root of (256x) expands to The square root of (256) times the square root of (x). The square root of 256 is 16, so that term becomes 9^4 * 16 square roots of x, then add the second tem 9^4 *9 square roots of x (simplified the same way as the first term). Use distributive property to rename this expression as 9^4 (the common factor divided out of each term) times the quantity (16 square roots of x plus 9 square roots of x), now simplify like terms in the quantity, and get 9^4 times the quantity 25 square roots of x, or more succinctly:
9^4*5^2 * the square root of x

Answer 2

I'll assume that the x is under the radical sign
Then √256 = 16
√81 = 9.
So we get 9^4(16 +9)√x.
or 25*9^4√x.

Answer 3

0.0 omg thats hard math...
um... i got 4. and whats that check mark thingy?