Answer
The regions represented by the given set are Quadrants I and III.
Work Step by Step
The product of the x and y coordinates of each point is greater than zero or positive.
The product of $x$ and $y$ will be positive only when $x$ and $y$ have the same signs.
Note that the x and y coordinates have the same signs in Quadrant I and Quadrant III.
Thus, the regions given by the set are Quadrant I and Quadrant III.