Řeš v ℝ soustavy nerovnic:
\( x+1\lt3x+3 \)
\( x\gt18 \)
\( \large K = \left( {-\infty;18} \right) \)
\( \large K = \left( {0;\infty } \right) \)
\( \large K = \left( {18;\infty } \right) \)
\( \large K = \left( {18;20} \right) \)
