Question

Lg(x2+2x+3)=lg3
A) -2,0
B) 2;0
D)-2;2

Answer 1

$lg(x^2+2x+3)=lg3 \\ x^2+2x+3 textgreater 0 \ xin(-infty;+infty) \\ x^2+2x+3=3 \ x^2+2x=0 \ x(x+2)=0 \ x_1=0; x_2=-2$

Ответ: А