Example

Writing the Inequality 2x+3y<62x + 3y < 6 from Its Graph

To derive the correct linear inequality from a graph showing the boundary line 2x+3y=62x + 3y = 6, one must evaluate the line type and the shaded region. Because the boundary line is dashed, the inequality is strict and will not contain an equal sign (<< or >>). To find the correct symbol, test a reference point in the shaded area, such as the origin (0,0)(0, 0). Substituting x=0x = 0 and y=0y = 0 into the left side of the equation yields 2(0)+3(0)=02(0) + 3(0) = 0. Since the shaded region indicates the solutions, the substitution must create a true mathematical statement. The comparison between 00 and the constant 66 is true when written as 0<60 < 6. Thus, the shaded region containing the origin represents the inequality 2x+3y<62x + 3y < 6.

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Updated 2026-05-06

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