How do we illustrate Inequalities on the Plane? There are several rules to follow:

Rule 1: If you're simply using the greater than ($>$) or less than ($<$) signs, the line should be dotted.

Rule 2: If you're using the greater than or equal ($\geq$) or less than or equal ($\leq$) signs, the line should be solid.

For Equations with both $x$ and $y$ present:

Rule 3: If you see a $y>mx+b$ or $y \geq mx + b$, shade ABOVE the line.

Rule 4: If you see a $y<mx+b$ or $y \leq mx + b$, shade BELOW the line.

For equations with only one variable present, either $x$ or $y$:

Rule 5: If you have an equation with only one variable, say $x < 5$, shade to the LEFT of the line. If you see $x > 5$, shade to the RIGHT of the line.

Rule 6: If you have an equation with only one variable, say $y < 5$, shade BELOW the line. If you see $y>5$, shade ABOVE the line.