To solve a system of inequalities, you can follow these steps in detail:
Step 1: Graph Each Inequality
- Convert each inequality to its boundary line:
- For a linear inequality like \( ax + by < c \), first rewrite it as an equation \( ax + by = c \) to find the boundary line.
- Determine the type of line:
- Use a dashed line for inequalities that use \( < \) or \( > \) (indicating that points on the line are not included).
- Use a solid line for inequalities that use \( \leq \) or \( \geq \) (indicating that points on the line are included).
- Shade the correct region:
- Choose a test point (commonly the origin \((0,0)\), if it’s not on the line) to see if it satisfies the inequality.
- If the test point satisfies the inequality, shade the area that includes the test point; otherwise, shade the opposite side.
Step 2: Identify Where the Two Regions Overlap
- After you have graphed all inequalities, look for the region where the shaded areas overlap. This overlapping section represents the solution to the system of inequalities.
Step 3: Any Point in the Overlapping Area is a Solution
- Any point (x, y) within the overlapping shaded region is a solution that satisfies all inequalities in the system. Identify several points within this region if needed for specific solutions.
Final Explanation
- The solution to a system of inequalities can be visualized as the intersection of multiple half-planes in the coordinate graph. Each inequality divides the plane into two half-planes, and the solutions are found in the region where all half-planes intersect.
Example
Consider the system of inequalities:
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\( y < 2x + 1 \)
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\( y \geq -x + 2 \)
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Graph: Graph the line \( y = 2x + 1 \) as a dashed line and shade below it.
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Graph the line \( y = -x + 2 \) as a solid line and shade above it.
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Overlap: Identify the region where the shading overlaps.
The points in this overlapping area are the solutions to the system of inequalities.