What is the cube root of -729a^9b^6

Well, cube root is basically x * x * x = y ( or in your case ? * ? * ? = -729 )

It should be easy to go thru the numbers to find out that -9 * -9 * -9 is -726.

9 and 6 don't have a cube root so, take what you can out of both.

The best you can do is b^2 since the cube root of 2*2*2 = 8

So far: -9b^2 and then with a you can do 3*3 = 6 so it's be:
a^3 ( since 9 - 6 = 3 and 6 - 4 = 2 )

-9a^3b^2.

You're not done, you have a left over of a^3 and b^2, so...

Your