we need to find the line equation for the dashed line. Since we have 2 points of the line, its slope is
where we used the slope formula:
Then, our searched line has the form:
where b is the y-intercept. We can finde b by substituting point (0,-3) into the last equation:
then, the searched line in slope-intercept form is
Therfore, the given area can be modeled as
because when a line is dashed it doesn't belong to the given area.