\(x^3+x^2+x+1=0\)
\(\Rightarrow\left(x^3+x^2\right)+\left(x+1\right)=0\)
\(\Rightarrow x.\left(x+1\right)+\left(x+1\right)=0\)
\(\Rightarrow\left(x+1\right).\left(x+1\right)=0\)
\(\Rightarrow\left(x+1\right)^2=0\Rightarrow x+1=0\Rightarrow x=-1\)
Vậy \(x=-1\)
Chúc bạn học tốt!!!
