Answer: half-plane.
- A half-plane
- B full plane
- C single line
- D single point
Correct answer: A. half-plane
Explanation: A linear inequality in two variables represents a half-plane bounded by the line x + y = 4.
One-variable inequalities use open (excluded) or closed (included) circles on a number line; two-variable inequalities use a dashed (strict) or solid (non-strict) boundary line, with the solution being the entire shaded half-plane on one side of it.
Concept context
Solving linear inequalities in one and two variables algebraically and graphically, and representing solutions on a number line or as a region in a plane.