Answer:
[tex] {9}^{ - 8} [/tex]
Step-by-step explanation:
[tex] \frac{ {9}^{ - 5} }{ {9}^{3} } [/tex]
[tex] {9}^{ - 5 - (3)} [/tex]
[tex] {9}^{ - 5 + (- 3)} [/tex]