А) \\\\\\\\\\\\\\\\\\\\\\\\\\
-------------------[-2]-----------------→
[]- сплошной кружок в точке х=-2
б)
х > 0
\\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------------------(0)-------------------------------→
() пустой кружок
x < 0<br>\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------------------(0)-------------------------------→
х ≥0
\\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------------------[0]-------------------------------→
x ≤ 0
\\\\\\\\\\\\\\\\\\\\\\\\\\\
--------------------[0]-------------------------------→