Answer :
[tex]\log(5x-5)=\log(2x+3)+\log15\\
\log(5x-5)=\log[15(2x+3) ], \text{ because } \log(ab)=\log a+\log b\\
\log(5x-5)=\log(30x+45)\\
5x-5=30x+45, \text{ because } (\log x=\log y\rightarrow x=y.)\\
-25x=50\\
\text{Then } x=-2.[/tex]