3xbình =(x+2) bình => 3x bình = x bìn+ 4 x +4 => 2x bình - 4x -4 =0 => 2. (x bình - 2x -1)=0
2. \(\sqrt{x^2+6x+9}=3x-6\)
\(\sqrt{\left(x-3\right)^2}=3x-6\)
\(x-3=3x-6\)
\(x-3-3x+6=0\)
\(-2x+9=0\)
\(-2x=-9\)
\(x=\frac{9}{2}\)
3. \(\sqrt{x^2-4x+4}-2x+5=0\)
\(\sqrt{\left(x-2\right)^2}-2x+5=0\)
\(x-2-2x+5=0\)
\(-x+3=0\)
\(x=3\)