Question 171127
Remember, the sum of the logs is the log of the product, or {{{log(b,(a))+log(b,(c))=log(b,(ac))}}}


So,


{{{log(10,(3x))=log(10,(5))+log(10,(x-4))}}}


{{{log(10,(3x))=log(10,(5(x-4)))}}}


but if {{{log(b,(a))=log(b,(c))}}} then {{{a=c}}} so:


{{{3x=5(x-4)}}}


{{{3x=5x-20}}}


{{{-2x=-20}}}


{{{x=10}}}