\[\boxed{\text{19.\ }\text{ОК\ ГДЗ\ -\ домашка\ на\ 5}}\]
\[\textbf{а)}\ x < 3\]
\[\textbf{б)} - 2 < x < 4\]
\[\textbf{в)}\ x \geq 1\]
\[\textbf{г)}\ 5 \leq x \leq 7,5\]
\[\textbf{д)}\ 0 < x \leq 2,5\]
\[\textbf{е)}\ x \geq 10,5\ \]