Решите уравнение log3(x+2) + log3(5x+4)=3

ОДЗ:
$\left \{ {{x+2\ \textgreater \ 0} \atop {5x+4\ \textgreater \ 0}} \right. \ \textless \ =\ \textgreater \ \left \{ {{x\ \textgreater \ -2} \atop {x\ \textgreater \ -0.8}} \right. \ \textless \ =\ \textgreater \ x\ \textgreater \ -0.8$

$log _{3} (x+2) + log_{3} (5x+4)=3 \\ log_{3} (x+2)(5x+4)=3 \\ 3 ^{3} =(x+2)(5x+4) \\ 5 x^{2} +4x+10x+8=27 \\ 5 x^{2} +14x-19=0 \\ D=196+380=576=24 ^{2} \\ x= \frac{-14+24}{10} =1 \\ x= \frac{-14-24}{10}=-3.8$
- не удовл. ОДЗ
отв:х=1