SAT Question 187f74bc: Linear Inequalities answer and explanation with Desmos solution

Choice D is correct. The line representing the boundary of the shaded region shown is a horizontal line; therefore, the equation of the line can be written as $y=-4$. Since the shaded region represents all of the points above this boundary line, it follows that the shaded region represents the solutions to the inequality $y>-4$. It's given that the shaded region shown represents the solutions to the inequality $ry<60$, where $r$ is a constant. The inequality $y>-4$ can be rewritten in the form $ry<60$ by multiplying both sides of the inequality by $-15$, which yields $(-15)y<60$. Therefore, the value of $r$ is $-15$.