The given expression is
[tex]\frac{x^{-9}}{x^{-8}}[/tex]To solve this division, we use the following power rule.
[tex]\frac{a^b}{a^c}=a^{b-c}[/tex]In words, we just have to subtract exponents.
[tex]x^{-9-(-8)}=x^{-9+8}=x^{-1}[/tex]Now, we use the negative exponent property which allows us to transform the exponent into a positive one.
[tex]x^{-1}=\frac{1}{x}[/tex]