To rotate a point \( P(x, y) \) 180 degrees counterclockwise about the origin, you can use the following rotation rule:
\[ P'(x, y) \rightarrow P'(-x, -y) \]
For the point \( P(4, -9) \):
- Apply the rotation rule: \[ P'(4, -9) = P'(-4, 9) \]
Thus, the coordinates of \( P' \) after a 180-degree rotation about the origin are \( P'(-4, 9) \).
The correct response is: \( P'(-4, 9) \)