Step-by-step explanation:
We will need to use logs here...
First divide each side by 3
[tex]3(10)^x=30000[/tex]
[tex]10^x=10000[/tex]
Then take the log of each side
Keep in mind that [tex]log_{10} (10)[/tex] gets canceled out to leave x
[tex]log_{10} (10^x)=log(10000)[/tex]
Finally, log(10000) = 4 because [tex]10^4=10000[/tex]
[tex]x = 4[/tex]