Rewrite the expression using the negative exponent rule .

Raise to the power of .

Rewrite as an equation.

Rewrite in exponential form using the definition of a logarithm. If and are positive real numbers and does not equal , then is equivalent to .

Create equivalent expressions in the equation that all have equal bases.

Since the bases are the same, the two expressions are only equal if the exponents are also equal.

The variable is equal to .

Evaluate log base 3 of (81)^-5