9 - MATH
MATHEMATICS HIGH SCHOOL STANDARDS FOR MATHEMATICAL CONTENT: BY CONCEPTUAL CATEGORY CONCEPTUAL CATEGORY
REASONING WITH EQUATIONS AND INEQUALITIES A-REI
B. SOLVE EQUATIONS AND INEQUALITIES IN ONE VARIABLE.
12. Graph the solutions of a linear inequality in two variables as a half-plane (excluding the boundary in the case of a strict inequality), and graph the solution set of a system of linear inequalities in two variables as the intersection of the corresponding half-planes.