boundary line	A line that divides the coordinate plane into two regions. If points along the boundary line are included in the solution set, then a solid line is used; if points along the boundary line are not included then a dotted line is used.
coordinate plane	A plane formed by the intersection of a horizontal number line called the x-axis and a vertical number line called the y-axis.
linear inequality	A mathematical statement in two variables using the inequality symbols <, >, ≤, or ≥ to show the relationship between two expressions. When the inequality symbol is replaced by an equal sign, the resulting related equation will graph as a straight line.