documentclass[border={1mm 1mm 1mm 1mm}]{standalone}
usepackage{tikz}
usetikzlibrary{patterns}

begin{document}
begin{tikzpicture}[scale=0.6]
draw[->] (-4.5,0) -- (1.5,0);
draw[->] (0,-4.5) -- (0,4.5);
foreach x in {-4,-3,-2,-1,0,1}
    draw (x cm,1.5pt) -- (x cm,-1.5pt);
foreach y in {-4,-3,-2,-1,0,1,2,3,4}
    draw (1.5pt,y cm) -- (-1.5pt,y cm);
    draw[thick,red,pattern=north east lines,pattern color=red] (-4,-4) -- (0,0)--(-4,4);
draw[draw=none,red,pattern=north west lines,pattern color=blue] (0,0)--(-4,4) -- (4,4)--(4,-4)--(-4,-4)--(0,0);
end{tikzpicture}
end{document}