Precalculus (6th Edition) Blitzer

Note that: $x^3$ is negative when $x$ is negative. $y^3$ is positive when $y$ is positive. This means that the points that satisfy the given statements must have a negative $x$ and a positive $y$. Points in Quadrant II have negative $x$ values and positive $y$ values. Thus, only points in Quadrant II satisfy the given statements.