We have the following equation,
[tex](\frac{1}{3})^x=18[/tex]By taking logarithm base 3 to both sides, we have
[tex]\log _3(\frac{1}{3})^x=\log _318[/tex]By the powers rule for logarithms, we get
[tex]x\cdot\log _3(\frac{1}{3})^{}=\log _318[/tex]Now, by the quotient rule, we have that
[tex]\begin{gathered} \log _3(\frac{1}{3})=\log _3(1)-\log _3(3) \\ \log _3(\frac{1}{3})=-\log _3(3) \end{gathered}[/tex]because base 3 logarithm of 1 is zero. Then, we have
[tex]-x\cdot\log _3(3)^{}=\log _318[/tex]But
[tex]\log _3(3)=1[/tex]then, we obtain
[tex]-x=\log _318[/tex]By multiplying both sides by -1, we have
[tex]x=-\log _318[/tex]Finally, since
[tex]\log _318=2.6309[/tex]The answer is x= - 2.6309