Question

como resolvo raiz de 2x+x²

Answer 1

2x +x² = 0 (colocar o x em evidencia)
x (2 + x) = 0
x = 0
2 + x = 0 
x = -2

Logo as raízes são 0 e -2   

Answer 2

     As raízes são os valores que assume a incógnita quando a função é nula
     Então
                      2x + x^2 = 0
         fatorando
                      x(2 + x) = 0
                             x = 0
                                                  x1 = 0
                           2 + x = 0
                                                  x2 = - 2
                                                                              S = { 0, - 2 }