Answer :
[tex]x^2+4x+3=0 \\\\ x^2+x+3x+3=0 \\\\ x(x+1)+3(x+1)=0 \\\\ (x+1)(x+3)=0 \\\\\\ x+1=0 \ \ \Longrightarrow \boxed{x=-1} \\\\ x+3=0 \ \ \Longrightarrow \boxed{x=-3}[/tex]
x² + 4x + 3 = 0
x² + 3x + x + 3 = 0
(x + 1)(x + 3) = 0
x + 1 = 0 or x + 3 = 0
- 1 - 1 - 3 - 3
x = -1 x = -3
x² + 3x + x + 3 = 0
(x + 1)(x + 3) = 0
x + 1 = 0 or x + 3 = 0
- 1 - 1 - 3 - 3
x = -1 x = -3