(I) \( 3^{-4} \cdot 3^{-2} \)

When multiplying numbers with the same base, you simply add their exponents! In your case, you have \( 3^{-4} \cdot 3^{-2} \). So, you combine the exponents: \( -4 + (-2) = -6 \). Therefore, \( 3^{-4} \cdot 3^{-2} = 3^{-6} \). Now, to rewrite it in a more standard form, remember that negative exponents indicate the reciprocal. So, \( 3^{-6} = \frac{1}{3^6} \), and if you compute \( 3^6 = 729 \), you get \( \frac{1}{729} \). Voilà!