Redraw the graft but make all the lines on it face the opposite direction. All ur really sowing is turning the graph 90 degrees. So the main line would be in the middle and horizontal. Then the two that cut through one would be straight vertical lines starting at point 2. Add the y line in the center. The other line is diagonal. It would cut thro the center and go up one at a time so if y=1 then x=1.