In the coordinate system, a point is located in quadrant IV if its x-coordinate is positive and its y-coordinate is negative. The coordinates of the point (x, -9) indicate that the y-coordinate is -9, which is indeed negative.
For the point to be in quadrant IV, the x-coordinate (x) must be positive. Therefore, any positive value for x would place the point (x, -9) in quadrant IV.
In summary, any value of \( x > 0 \) will ensure that the point (x, -9) is located in quadrant IV.