Question

(x+1)$(x+1)^{2}=9$

Answer 1

$(x+1)^2=9\\ (x+1)=\pm \sqrt{9}\\(x+1)=\pm3\\\\ \begin{cases}x+1=3~~~~~x+1=-3\\ x=3-1~~~~~x=-3-1\\ x_1=2~~~~~~~~~x_2=-4\end{cases} \\\\\\ \Large\boxed{\text{S}=\{2,-4\}}$