You can put this solution on YOUR website! I am not sure I understand how the problem is written however if you want the cube root of (5b)^9 which is what I think you are asking given my experience with Algebra texts ;)
realize that (5b)^9 = (5b)^3*(5b)^3*(5b)^3 so your answer is (5b)^3
Please let me know if you need more help