4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example : If log2x = log27, then

Solving Logarithmic Equations

Key Concept

logbx = logby if and only if ________.

4.6 Continued

Example 1:

Solve log5 (4x - 7) = log5 (x + 5)

4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example 2:

Solve 2 lnx = ln(2x - 1)

Example 3:

Solve log3 (x2 + 7x - 5) = log3 (6x + 1)

4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example 4:

Solve log4 (5x - 1) = 3

Example 5:

Solve log6 (17x + 2) = 2

4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example 6:

Solve log (x + 48) + log x = 2

Example 7:

Solve log x + log (x + 3) = 1

4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example 8:

Solve log2 4x + log2 (x + 3) = 4

Now Solving by Graphing

4.6 Solving Logarithmic Equations.notebook May 05, 2015

4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example 9: Solve log (x + 48) + log x = 2 by graphing.

4e3x-5 = 72

Example 10: Solve using graphing

4.6 Solving Logarithmic Equations.notebook May 05, 2015

Example 11: Solve using graphing

log5 (x2 + 7x - 5) = log5 (6x + 1)

Assignment: p. 272 # 18, 22, 26, 30, 38, 42, 48, 51

*Solve # 48, 51 by graphing.

4.6 Solving Logarithmic Equations.notebook May 05, 2015