The related boundary line of $\displaystyle{y}\le{x}\usepackage{cmbright}\Huge\$ is $\displaystyle{y}={x}\usepackage{cmbright}\Huge\$ . This line has a slope of 1 and goes through (0, 0). Because the boundary line is included in the solution, it is a solid line. The ordered pair (0, $\displaystyle-{1}\usepackage{cmbright}\Huge\$ ), for example, is a solution. Therefore, the shaded region will be below the line.