To find the new coordinates of point Q(-5, -9) after a rotation of -270° about the origin, we can first convert the angle to a positive angle.
-270° is equivalent to +90° since rotating clockwise is negative and counter-clockwise is positive.
To rotate a point (x, y) by 90° counter-clockwise about the origin, the new coordinates (x', y') are given by:
- \( x' = -y \)
- \( y' = x \)
Now, applying these transformations to the point Q(-5, -9):
- \( x' = -(-9) = 9 \)
- \( y' = -5 \)
Thus, the new coordinates after rotating Q(-5, -9) -270° (or +90°) about the origin are Q'(9, -5).
Therefore, the correct answer is: D. Q' (9, -5)