The change of base rule can be used if and are greater than and not equal to , and is greater than .

Substitute in values for the variables in the change of base formula, using .

Rewrite as .

Expand by moving outside the logarithm.

Rewrite as .

Expand by moving outside the logarithm.

Cancel the common factor.

Rewrite the expression.

The result can be shown in multiple forms.

Exact Form:

Decimal Form:

Evaluate log base 9 of 25