Normally, the first thing you do is establish the border line, by changing the > into an =. However, in all 4 answers, the line is the same, so that is not what the question is about. We need to know two things:
- do we need to be on the left or the right side of the line to find points that satisfy the equation? - is the line itself included or not
To start with the second question, since y has to be greater than and not equal, the line itself is NOT included in the solution area. This means the correct answer has to have a dashed line.
The general way to know on which side of the line you have to be, is to fill in one easy point and see if the equation holds. Let's fill in (0,0), (but any point will do).
you get: 0 > 1 - 3*0, which is NOT true. So (0,0) is in an area that is not our solution. The top-right picture is therefore not the answer.
What remains is the bottom-right picture, that is the correct shaded area. All points in the shaded area satisfy the equation.
