Answer:
for "a is less than or equal to -8", you would plot a point, colored in, at -8 and draw an arrow going left. for "a is greater than or equal to -6", plot a colored in point at -6, and draw an arrow going right. the reason the points need to be colored in is because the equations have the line that represent "or equal to". if there was no line, you would leave the point not colored in.
hope this helps!