Example

Solving {x2y<5,  y>4}\{x - 2y < 5,\; y > -4\} by Graphing

Solve the system {x2y<5y>4\left\{\begin{array}{l} x - 2y < 5 \\ y > -4 \end{array}\right. by graphing.

Graph x2y<5x - 2y < 5. The boundary line is x2y=5x - 2y = 5, which has intercepts x=5x = 5 and y=2.5y = -2.5. Because the inequality uses << (strict), draw a dashed line. Test (0,0)(0, 0): 02(0)<50 - 2(0) < 5 gives 0<50 < 5, which is true. So shade the side that contains (0,0)(0, 0).

Graph y>4y > -4 on the same grid. The boundary line is y=4y = -4, a horizontal line passing through y=4y = -4. Because the inequality uses >> (strict), draw a dashed line. Test (0,0)(0, 0): 0>40 > -4 is true. So shade the side that contains (0,0)(0, 0).

Identify the solution. The point (0,0)(0, 0) lies in the overlapping region and has already been verified as a solution of each inequality. The point where the two boundary lines intersect is not included in the solution because both boundary lines are dashed. The solution is the region where both shadings overlap — the darker-shaded area.

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Updated 2026-04-21

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