Q is the set of the rational numbers
Rational numbers are all numbers that can be put in the form of a/, where b is not equal to zero.
Examples:
[tex]\frac{3}{4},5\frac{2}{7},5.4,2[/tex]The given equation is
[tex](\frac{1}{5})^x=2[/tex]Insert log on both sides
[tex]log\mleft(\frac{1}{5}\mright)^x=log\mleft(2\mright)[/tex]Use the rule of power with a log
[tex]xlog(\frac{1}{5})=log\mleft(2\mright)[/tex]Divide both sides by log(1/5)
[tex]\begin{gathered} x=\frac{log\mleft(2\mright)}{log\mleft(\frac{1}{5}\mright)} \\ x=-0.43067655 \end{gathered}[/tex]Since we can not put the value of x in the form of a/b, then
The equation has NO solution in Q (or empty set { } or Nul)
