Answer:
x = - [tex]\frac{1}{4}[/tex]
Step-by-step explanation:
Using the rules of exponents
[tex](a^m)^{n}[/tex] = [tex]a^{mn}[/tex] , [tex]a^{-m}[/tex] = [tex]\frac{1}{a^{m} }[/tex]
Given
[tex]81^{x}[/tex] = [tex]\frac{1}{3}[/tex] [ note that 81 = [tex]3^{4}[/tex] ] , then
[tex](3^4)^{x}[/tex] = [tex]3^{-1}[/tex] , that is
[tex]3^{4x}[/tex] = [tex]3^{-1}[/tex]
Since the bases on both sides are equal, both 3, then equate exponents
4x = - 1 ( divide both sides by 4 )
x = - [tex]\frac{1}{4}[/tex]
