Question

log3 (x^2+3x) = log 3 (5x+8)

Answer 1

$log_3 (x^2+3x) = log_3 (5x+8)$
ОДЗ: $x(x+3) textgreater 0; left { {{x textgreater 0} atop {x textless -3}} right.$
$5x+8 textgreater 0;x textgreater -1.6$

$x textgreater 0$

$x^2+3x=5x+8$
$x^2-2x-8=0$
$(x-4)(x+2)=9$
$x_1=4;x_2=-2$

С учетом ОДЗ: $x=4$