Simplify (3^−2 − 2^−2)^−1

Question

The answer is -36/5 I just need to know how to do it.

Answer 1

3^-2 = 1/3^2 = 1/9
2^-2 = 1/2^2 = 1/4

1/9 - 1/4 = -5/36

(-5/36)^-1 = 1/(-5/36) = -36/5