Answer:
The correct option is A.
Step-by-step explanation:
The given expression is
[tex]9^{-2.5}[/tex]
It can be written s
[tex]9^{-2.5}=\frac{1}{9^{2.5}}[/tex] [tex][\because x^{-n}=\frac{1}{x^n}][/tex]
[tex]9^{-2.5}=\frac{1}{(3^2)^{2.5}}[/tex]
[tex]9^{-2.5}=\frac{1}{3^5}[/tex] [tex][\because (x^m)^{n}=x^{mn}][/tex]
[tex]9^{-2.5}=\frac{1}{243}[/tex]
The value of given expression is [tex]\frac{1}{243}[/tex].
Therefore the correct option is A.
