Answer
A,C,D
Work Step by Step
$5^{x}=9\Rightarrow x=\log _{5}9$
$5^{x}=9\Rightarrow \log 5^{x}=\log 9\Rightarrow x\log 5=\log 9\Rightarrow x=\dfrac {\log 9}{\log 5}$
$5^{x}=9\Rightarrow \ln 5^{x}=\ln 9\Rightarrow x\ln 5=\ln 9\Rightarrow x=\dfrac {\ln 9}{\ln 5}$
So A,C,D are solution set