Algebra 1: Common Core (15th Edition)

We need to get the variable alone. In order to cancel out multiplication, we use division, so we divide both sides of the inequality by -3. However, because we divide by a negative, we must flip the inequality sign. Thus, we obtain that $x \leq -3$. This means that the graph should be shaded for all values less than or equal to -3, making C the correct graph.