`\sqrt{x^2+2x+1}=\sqrt{x+1}`
Điều kiện:`x>=-1`
`pt<=>\sqrt{(x+1)^2}=\sqrt{x+1}`
`<=>\sqrt{x+1}(\sqrt{x+1}-1)=0`
`+)\sqrt{x+1}=0<=>x=-1`
`+)\sqrt{x+1}=1<=>x=0`
Vậy `S={0,-1}`
\(\sqrt{x^2+2x+1}=\sqrt{x+1}\)
=>\(x^2+2x+1=x+1\)
<=>\(x^2+x=0\)
<=>\(x\left(x+1\right)=0\)=>x=1 hoặc x+1=0=>x=-1
√x2+2x+1 =√x+1 ĐK x≥-1
<=>x2+2x+1=(√x+1)2
<=>x2+2x+1=x+1
<=>x2+x=0
<=>x(x+1)=0
<=>x=0
x+1=0
<=>x=0 (TM)
x=-1 (TM)