Question 230699
Hi, 
I hope I understand the problem correctly. 
I take it that the -1 is the power of the fraction 2/9.

So the get rid of the -1 power you move the fraction 2/9 to the denominator
like this:

        1/ 2/9 to the first power. the negative -1 turns to positive 1

This can be further simplified since 1 over the fraction 2/9 can be rewritten as 
 9/2 or  reduced further to  4 1/2. 

Hopes this help. 

RJ Toftness
www.math-unlock.com