Before we begin solving log equations, it's important to review the definition of a logarithm.
Remember, a logarithm is just an exponent, but written in a different form:

For the simplest logarithmic equations, if you remember this definition of a logarithm and convert the equation from log form to exponential form, you will probably be able to solve it using just a few steps.

Example 1

Solve the equation log₂ x = -4.

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x = numerator 1 denominator 16 1 16

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Example 2

Solve the equation log₉ 27 = x.

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x = numerator 3 denominator 2 3 2

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Example 3

Solve the equation log_x 25 = numerator 2 denominator 3 2 3 .

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x = 125

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Now that you've seen the three examples, try solving these problems on your own. You should use scratch paper and your calculator. Click to reveal the solutions.

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