Respuesta :
Here's a rule that applies to this expression:
- Dividing exponents of the same base: [tex] \frac{x^m}{x^n}=x^{m-n} [/tex]
For this, just divide:
[tex] \frac{3^{-9}}{3^{-12}}=3^{-9-(-12)}=3^3 [/tex]
Your answer is 3^3, or the third option.