Well I've tried equating to $x$ i.e. $$3^x =0.095,$$
then taking both side to $\log_{10}$, so we have $$\log_{10}3^x =\log_{10}0.095$$, then I crossed $x$ to the other side ,i.e., $$x\log_{10}3=\log_{10}0.095.$$
Then I divided both sides by $\log_{10}3$.
Meaning that $$x =\frac{\log_{10} 0.095}{ \log_{10}3}$$
Then i solved on but didn't get the answer and I was confused, our head of study group says the answer is $-2.14$. Guys help , pls its not a homework