Question

How do you write:

-1/9 x^-1 with a positive exponent?

also, -5 x^-2 ??

Answer 1

-1/9 * x^-1= -1/(9x)

-5x^-2= -5/x^2

It is very difficult for tell what is where in your problem statement without the use of grouping symbols ( )

For instance, you might have meant
-1/(9x^-1)

or

(-5x)^-2 or -(5x)^-2

which all have quite different answers.