[tex](x+1)^2 = 16~~~~~~~| \sqrt{~} \\ \\
\sqrt{(x+1)^2} = \sqrt{16} \\ \\
x+1 = \pm 4 \\ \\
x = \pm 4 -1 \\ \\
x_{_1} = 4 - 1 = \boxed{3} \\ \\
x_{_2} = -4 - 1 = \boxed{-5} \\ \\
\Longrightarrow ~~ \texttt{Solutia negativa este: } ~ \boxed{\boxed{-5} }[/tex]
