Worksheet Change of Base Formula Name: College Prep Math 2 I. Use a calculator to approximate each to the nearest thousandth (4 decimal places) log 6 40 1. log 4 3.5 2. log 2 2.9 3. log 7 8.7 4. II. Solve each of the following equations using the change of base formula. 12 x = 13 5. 16 x = 65 6. 11x − 8 − 5 = 54 7. 16 x − 7 + 5 = 24 8. 20 −6 x + 6 = 55 9. 5 ⋅ 6 3x = 20 10. 8 −5 x − 5 = 53 11. −19 + 5 2 x − 4 = 2 12.