Řeš v ℝ rovnice pomocí rozkladu na součin:
\large x^{2} + 4 x + 4 = 0
\left. {K = \left\{ { 0} \right.} \right\}
\left. {K = \left\{ { – 4} \right.} \right\}
\left. {K = \left\{ { 2} \right.} \right\}
\left. {K = \left\{ { – 2} \right.} \right\}