Question

Помогите решить логарифм log2(3х-1) = log2(х-3) + log25

Answer 1

$\log_2(3x-1)=\log_2(x-3)+\log_25\\ O.D.3.\,\,\, \left \{ {{3x-1\ \textgreater \ 0} \atop {x-3\ \textgreater \ 0}} \right.\Rightarrow \left \{ {{x\ \textgreater \ \frac{1}{3} } \atop {x\ \textgreater \ 3}} \right. \Rightarrow x\ \textgreater \ 3$
 $\log_2(3x-1)=\log_2(5x-15)\\ 3x-1=5x-15\\ 5x-3x=-1+15\\ 2x=14\\ x=7$

Answer 2

Log₂(3x-1)=log₂(x-3)+log₂5
log₂(3x-1)=log₂(5x-15)
3x-1=5x-15
2x=14
x=7.