the +1 at the end of the equation is the y intercept while the number with the x is the slope, since the slope is -1/3 take it as if it was rise/run. In other words since the rise is -1 you are going down 1 unit and the run is 3 you are going 3 units to the right & that's the path its going to be taking. So that makes the line cross the x axis at (0,3)
