The inequality is first converted to its standard form, y=mx+b, where the slope "m" may then be determined by inspecting the equation (for example, in the equation "y=-2x+4" "-2" is the correct value for "m").

Any pair contained in the shaded region is a valid pair for the inequality, any pair along the dotted line is invalid and any pair outside of the shaded region is not valid.  So, there are an infinite number of possible values for valid or invalid pairs.