Solve log base 3 of 81 equals x

Log (base3) 81 = x

One of the log identities is

Log (base x) x = 1

We can rewrite 81 in terms of 3 so that we can use the identity.

Log (base 3) 3^4 = x

The power rule lets us bring the 4 in front as a coefficient so,

4 * log (base3) 3 = 81

4 * 1 = x

4 = x