In the Cartesian coordinate system, Quadrant IV is defined where the x-coordinate is positive and the y-coordinate is negative. Since the ordered pair is (x, -9), the y-coordinate is -9, which is negative.
For the ordered pair to be in Quadrant IV, the x-coordinate (x) must be positive.
Let's evaluate the options: A. -7 (negative, does not satisfy) B. 8 (positive, satisfies) C. 0 (neither positive nor negative, does not satisfy) D. -1 (negative, does not satisfy)
The only value of x that keeps the ordered pair (x, -9) in Quadrant IV is B. 8.