In a graph, the boundary line \(ax+by=c\) is solid, and the region on the side where \(ax+by\) is less than \(c\) is shaded. Which inequality does it represent?

Correct answer: \(ax+by\le c\)

A solid boundary means points satisfying \(ax+by=c\) are included. The shaded side has smaller values, so the inequality is \(ax+by\le c\). With \(<\), the boundary would be dashed. Exam tip: a solid line indicates equality.