Answer:
p = -2
Step-by-step explanation:
Start by dividing both sides by 81 to get the power by itself.
[tex]3^p \cdot 81 = 9\\\\3^p=\frac{9}{81}=\frac{1}{9}[/tex]
Write the fraction using a power of 3.
[tex]3^p=\frac{1}{3^2}\\\\3^p=3^{-2}\\\\p=-2[/tex]
This assumes you know about negative exponents: [tex]a^{-n}=\frac{1}{a^n}[/tex]