Chapter 6 - Systems of Equations and Inequalities - 6-5 Linear Inequalities - Practice and Problem-Solving Exercises - Page 398: 34

$x \lt 3$

Since the graph is a vertical line, m could be infinity or undefined. The boundary line is dashed, so the inequality symbol is either $\lt$ or $\gt$. Since the line is shaded to the left, we have to use $\lt$. There is no y-intercept, and the x-intercept is $3$; therefore, the inequality is $x \lt 3$.