[Tex/LaTex] How to draw intervals in latex using tikz or otherwise

Question

Sometimes we require to represent multiple intervals on a single number line so that we could see their intersection easily. One illustration is given below

I can draw line and make nodes using tikz but I don't know how to draw line segments above the number line.

Please help me.

Answer 1

One way to draw the line segments that are above the number line is to draw the line segment first \draw (x1,y) -- (x2,y) and then put circles with filling over them using \draw[fill=white] (x,y) circle (radius) for a white circle or \fill (x,y) circle (radius) for a black circle. So the final code would look something like this

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
    \begin{tikzpicture}[scale=0.5]
    \draw (-12,0)-- (9,0); %Axis
    \foreach \x in {-10,1,5,7} {
        \draw (\x,0.5) -- (\x,-0.5) node[below] {\x};
    }
    \draw (-10,1) -- (5,1);
    \draw[fill=white] (-10,1) circle (0.25);
    \fill (5,1) circle (0.25);
    \draw (1,2) -- (7,2);
    \fill (1,2) circle (0.25);
    \draw[fill=white] (7,2) circle (0.25);
    \end{tikzpicture}
\end{document}

EDIT

Denis in the comments section suggested changing \draw (\x,0.5) -- (\x,0.5) node[below] {\x}; to \draw (\x,0.5) -- (\x,0.5) node[below] {$\x$}; to get a mathematical minus sign. However upon doing this the -10 becomes off centred too much for my liking. To recenter the number you can add a phantom (invisible) minus character after the 10 to recenter it. This is done by writing \draw (-10,0.5) -- (-10,0.5) node[below] {$-10\hphantom{-}$};

Therefore the final code can be written as:

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
    \begin{tikzpicture}[scale=0.5]

    \draw (-12,0)-- (9,0); %AXIS
    \foreach \x in {1,5,7} {
        \draw (\x,0.5) -- (\x,-0.5) node[below] {$\x$};
    }
    \draw (-10,1) -- (5,1);
    \draw[fill=white] (-10,1) circle (0.25);
    \fill (5,1) circle (0.25);
    \draw (1,2) -- (7,2);
    \fill (1,2) circle (0.25);
    \draw[fill=white] (7,2) circle (0.25);
    \draw (-10,0.5) -- (-10,-0.5) node[below] {$-10\hphantom{-}$};
    \end{tikzpicture}
\end{document}

Which yields: