TeX джерело:

\left\{ \begin{array}{l}5x - x \le - 6,\\3x - x \le 17 - 12;\end{array} \right.\quad \left\{ \begin{array}{l}4x \le - 6,\\2x \le 5;\end{array} \right.\quad \left\{ \begin{array}{l}x \le 1,5,\\x \le 2,5.\end{array} \right.