I want a grid that has no gridlines on the edges, hence I set the following code to have domains and ranges to be odd numbers. However, setting minor tick, you can see in the picture that the minor tick appears on the top and
\documentclass{article}
\usepackage{pgfplots}
\usetikzlibrary{intersections}
\usetikzlibrary{patterns}
\usetikzlibrary{arrows}
\begin{document}
\begin{enumerate}
\item Find the slope and $y$-intercept of this graph.\\
\begin{tikzpicture}[E/.style={font=\small,text=black, sloped, pos=0.75}]
\begin{axis}[axis line style=thin,
axis x line=center,
axis y line=center,
ytick={-6,-4,...,6},
xtick={-6,-4,...,6},
ymin=-7, ymax=7, xmin=-7, xmax=7, xlabel=$x$, ylabel=$y$, grid=both,minor tick num=3, y post scale=1]
\addplot[name path=A,domain=-7:7, samples=100, thick] { 3*x/4-3} node[E,above] {};
%\addplot[name path global=line1, color=blue!50, thick, domain=-7:9]{5-3*x/5};
\end{axis}
\end{tikzpicture}
\end{document}