y is dependent on what you pick for x. So there's an infinite number of solutions. When connected, they form a straight line. But there's a shortcut here built into this y equals mx plus b formula that tells you how to graph the line. The first point is this. This is where it crosses the y intercept. This is the y-axis.
So you go down to negative two. There is one point on that line. This is the slope. It tells you how many to go up: 1, 2, 3, 4 over 1; 1, 2, 3, 4 over 1, and go for infinity as it'll go on forever. There’s your line. Connect the dots, put your little arrowheads on it so that tells the person looking at it that you're talking about infinity.