1. Warm-up 12-7 1) Condense 3log 2 2 – ½ log 2 64

2. Lesson 12-7 Exponential and Logarithmic Equations Objectives Solve exponential & logarithmic equations Solve problems involving exponential and logarithmic formulae

3. Solving Exponential Equations 5 x = 7 Take the LOG of both sideslog 5 x = log 7 Use LOG propertiesx log 5 = log 7 Solve for x x = 1.2091 Example 1 Solve 3 5x – 2 = 27

4. Solving LOG Equations log(x – 1) + log(x + 1) = 1 Condense to a single LOGlog((x – 1)(x + 1)) = 1 Convert to exponential10 1 = (x – 1)(x + 1) Solve for x10 = x 2 – 1 11 = x 2 is the only answer as the x-values are positive

5. Example 2 Solve log(x + 2) + log(x – 2) = 1

6. EXP-Log Formulae Amount, Principal rate, time → → Loudness, Intensity I 0 = minimum intensity → R = magnitude, Intensity I 0 = minimum intensity

7. Example 3 How long for $1000 to double at 8%? HW 120