Le problem

\documentclass{standalone}
\usepackage{tikz,pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
    scale only axis,
    grid=major,
    width=11cm,
    unit vector ratio=1 1 1,
    enlargelimits=true,
    grid style={dashed, gray!30},
    axis lines=middle,
    inner axis line style={-stealth},
    xlabel={\large $x$},
    ylabel={\large $y$},
    yticklabel style={inner ysep=0pt, anchor=south east},
    ytick={-1,0,1},
    xticklabel style={inner xsep=0pt, anchor=north west},
    xtick={-5,-4,...,5},
    ymin=-1.5,
    ymax= 1.5,
    xmin=-5.5,
    xmax= 5.5,
after end axis/.code={
        \path (axis cs:0,0)
            node [anchor=north west,yshift=-0.075cm] {0}
            node [anchor=south east,xshift=-0.075cm] {0};
    }
]
\addplot[mark=none,color=red,domain=-5:5,thick] {x/8};
\end{axis}
\end{tikzpicture}
\end{document}