Question

Cum se determina log5(3x+4)=2

Answer 1

[tex]log_{5}(3x+4)=2\\ Conditia\ de\ existenta:3x+4>0=>x>- \frac{4}{3}=>x\in( - \frac{4}{3};+\infty)\\ log_{5}(3x+4)=2\cdot log_55\\ log_{5}(3x+4)=\cdot log_55^2\\ log_{5}(3x+4)=\cdot log_525\\ 3x+4=25\\ 3x=21\\ x=7\in( - \frac{4}{3};+\infty)[/tex]