-- Get the inequality into the form with 'y' on one side and everything else on the other side.
-- Graph it as if it were an equation. That gives you a line.
-- If the inequality is " y less than... ", then the graph of the inequality is all of the infinite plane under the line, but not the line itself.
-- "y less than or equal to ..." . . . . . the line and all of the area under it
-- "y greater than ... " . . . . . all of the infinite plane above the line, but not the line itself.
-- "y greater than or equal to ..." . . . . . the line and all of the area above it.
