## Intermediate Algebra for College Students (7th Edition)

$4C$
Note that $81=3^4$. Thus, the given expression is equivalent to: $=\log_b{(3^4)}$ RECALL: (1) $\log_b{(\frac{m}{n})} = \log_b{m} - \log_b{n}$ (2) $\log_b{mn} = \log_b{m} + \log_b{n}$ (3) $\log_b{(m^n)} = n \cdot \log_b{m}$ Use rule (3) above to obtain: $=4\log_b{3}$ With $\log_b{2} = A$ and $\log_b{3}=C$, the expression above is equivalent to: $=4C$