Answer:
4
Step-by-step explanation:
Define [tex]\log_a b=c\implies a^c=b[/tex].
Let
[tex]\log_3 81=x[/tex].
Using our definition [tex]\log_a b=c\implies a^c=b[/tex], we have:
[tex]3^x=81[/tex]
Solving for [tex]x[/tex]:
[tex]x=\boxed{4}\text{ from simply knowing that }3^4=81[/tex]
Or
Algebraically solve step-by-step by taking the log of both sides:
[tex]\log 3^x=\log 81[/tex]
Using log property [tex]\log a^b=b\log a[/tex], rewrite:
[tex]x\log 3=\log81[/tex]
Divide both sides by log(3):
[tex]x=\frac{\log 81}{\log 3}=\boxed{4}[/tex]
