Section 7.5: Review & Assessment
This section provides review exercises and assessment questions covering all topics of logarithms, including laws, equations, and applications.
Example 1: Applying Logarithm Laws
Simplify \( \log_2 8 + \log_2 4 \).
Step 1: Use product rule: \( \log_2 8 + \log_2 4 = \log_2 (8 \cdot 4) \)
Step 2: Multiply: \( 8 \cdot 4 = 32 \)
Step 3: Evaluate: \( \log_2 32 = 5 \)
Example 2: Solving Logarithmic Equation
Solve for x: \( \log_3(x-1) = 2 \)
Step 1: Rewrite in exponential form: \( x-1 = 3^2 \)
Step 2: Simplify: \( x-1 = 9 \)
Step 3: Solve: \( x = 10 \)
Practice Problems
- Simplify \( \log_5 25 - \log_5 5 \)
- Solve \( \log_4 (x+3) = 3 \) for x
- Evaluate \( \log_2 16 - \log_2 4 + \log_2 2 \)
- Solve \( \log_7 x + \log_7 2 = 3 \) for x
- Word Problem: The intensity of sound doubles. By what amount does \( \log I \) change?