The base of a logarithm should always be positive and can't be equal to 1, so the domain is 0 < <em>x</em> < 1 or <em>x</em> > 1.
Write both sides as powers of 1/<em>x</em> :
Recall that , so that
Take the 5th root of both sides, recalling that 3⁵ = 243, so
