Řeš v ℝ rovnice:
\large \left( x-\sqrt 2 \right) \left( x + 2\right) = 0
\large K = \left \{{ - 2;\sqrt 2 } \right \}
\large K = \left \{{ - 2; -\sqrt 2 } \right \}
\large K = \left \{{ 2;\sqrt 2 } \right \}
\large K = \left \{{ - 2; 2 } \right \}