${x}^{2}+2x+1-{x}^{2}=0$
Since two opposites add up to $0$, remove them from the expression$2x+1=0$
Move the constant to the right-hand side and change its sign$2x=-1$
Divide both sides of the equation by $2$$\begin{align*}&x=-\frac{ 1 }{ 2 } \\&\begin{array} { l }x=-0.5,& x=-{2}^{-1}\end{array}\end{align*}$