Fill in the blanks.
An ordered pair $ (a, b) $ is a ________ of an inequality in $ x $ and $ y $ if the inequality is true when $ a $ and $ b $ are substituted for $ x $ and $ y $ respectively.
The ________ of an inequality is the collection of all solutions of the inequality.
The graph of a ________ inequality is a half-plane lying on one side of the line $ ax + by = c $.
A ________ of a system of inequalities in $ x $ and $ y $ is a point $ (x, y) $ that satisfies each inequality in the system.
A ________ ________ of a system of inequalities in two variables is the region common to the graphs of every inequality in the system.
The area of the region that lies below the demand curve, above the horizontal line passing through theequilibrium point, to the right of the $ p $-axis is called the ________ _________.